The F650 FAQ - 
MOSTLY for the 1994 - 2000 carbureted BMW F650
(But there is some universally applicable stuff here.)

Disclaimer: Nothing constructive ever gets done by a committee, especially a virtual one.  Therefore, I took it upon myself to assemble this FAQ.  This is one person's opinion of questions that are often asked about BMW F650 motorcycles.  This opinion is mine and protected by the first amendment to the Constitution of the United States of America.  If you don't like it, you have two options... put up your own website with alternative opinions or send me email to discuss it.  If you have some constructive criticism or have something you would like to contribute, great. Send me an email.  

Last updated 18 July '01

There is lots more info like common replacement part numbers and write-ups on doing common maintenance and repair tasks listed in the Tech Tips Page of the Chain Gang. F650 riders tend to prefer to avoid paying BMW prices whenever possible.

Q: Is there a club somewhere for F650 owners?
A: The Chain Gang has a great website. The best part is the messageboard.

Q: How do people embed links in their messages on the Chain Gang Messageboard?
A: It is easy. Just follow the example.

Q: What about tires?
A: Look at David #476's F650 Tire FAQ.

Q: I was thinking about getting a new fuel injected F650 GS or Dakar.  Is there anything I should watch out for?
A: This is a hot topic. But if you've already bought one and it surges and stalls, you'll be happy to know that there is a fix.

Q: My bike acts like it is running out of gas when the tank gets low.   Putting it on reserve doesn't help.  Opening the gas cap helps for a little while.  What is up with that?   
A: You need a canisterectomy.

Q: My carbureted bike surges and stalls sometimes, particulary in the rain. What is up with that?   
A: They had some bozo working at the factor in Noale who hooked the hoses up to the right side carb bassakwards. First check to see that your hoses are hooked up right..

Q: I don't know much about chains.  How do I know when it is worn out, how to care for it and so forth?
A: See the chain primer below

Q: I bought a standard 120 link chain and/or changed the number of teeth on either or both of my sprockets.  How do I figure out where to cut the chain?
A: See the instructions below on fitting a chain.

Q: How do I go about installing an aftermarket shock absorber?
A: See the report below on installing an Ohlins shock.

Q: The stock horn blows.
A: Mount Fiamms or Hellas.

Q: How do I change my fork oil? (Or lower my forks?)
A: Harl tells you how to change your fork oil.

Q: How do I service my air filter?
A: Look below at the air filter info.

Q: How do I pull the carbs?
A: Out the top.

Q: BMW wants TWO HUNDRED DOLLARS for a lousy set of heated grips.  Is there another option?
A: Sure, in fact there are a couple of options for hot grips for under US$50.

Q: Isn't there an aftermarket service or workshop manual available for my bike?
A: Parlez vous francais?

Q: My bike peed gasoline all over the floor and is impossible to start.  What is up with THAT?
A: Pukin' petrol.

Q: Why did my pre-'97 bike countershaft sprocket fall off?
A: Because some idiot at BMW specified the wrong type of snap-ring.

Q: My water pump weephole leaks.  My coolant level drops.  My oil level rises.  My oil looks like chocolate instead of oil. WTF?!
A: Your water pump seals are shot.  It is not at all hard to rebuild your water pump yourself.

Q: How do you know if your wheel bearings are shot?
A: Feel them.

Q: How can I make my bike quit backfiring, particularly on trailing throttle?
A: There are a couple of approaches.

Q: Got any performance mods?
A: Sure.

Q: Got any actual maintenance tips?
A: Sure, Kristian's F650 Maintenance/Work Tips covers:
1. Clutch cover removal and possible reasons why it won't come off.
2. Wheel Bearings and Idler Arm Bearings & Seals.
3. Other Modifications/Repairs.
The intent is to provide more detailed information on how to do some basic maintenance tasks, as well as to give part numbers for generic parts such as bearings and seals, available (much cheaper and often BETTER quality) from sources other that BMW.

Q: How in heck do you get the fairing off this thing?
A: Follow the procedure and keep your bolts straight.

Q: How in the HECK do you do an oil & filter change on a fuel injected GS or Dakar?
A: You look at the GS Oil Change FAQ.

Q: What is the deal with this guy "Flash" and that book he sells on his website?
A: See the review below.

by Flash #412

To embed a link in a message posted to the Chain Gang Messageboard which pops open a new browser window, cut and paste one of these examples. You'll need to replace the stuff in caps with your own stuff. (Caps are not needed unless required by the server handling the URL.)
Start of sentence <a href="http://URL_HERE"target="_blank">BLUE UNDERLINED LINK</a> rest of sentence.
To embed a link in a message posted to the Chain Gang Messageboard which opens in the message frame, leave off the target="_blank" like this:
Start of sentence <a href="http://URL_HERE">BLUE UNDERLINED LINK</a> rest of sentence.
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Note: Netscape might display "& lt" and "& gt" (without the spaces) instead of "<" and ">". You are supposed to have the SIGNS not the "& gt" stuff to get it to work.

by Flash #412 (May '01)

The 2001 F650, GS or Dakar can be a great bike. There are those who love theirs and never had any problems. But individual units, BMW claims the number is one in six, can be a nightmare of surging and stalling. Before you buy from a dealer, it is suggested that you investigate the lemon laws in the relevant state for 650cc motorcycles. These laws vary widely and you would be best served to understand your rights and responsibilities before you get involved. Before you buy from anyone (new or used), you should arrange to ride the EXACT BIKE you will be purchasing. If it surges and/or stalls, RUN away. The dealer will likely tell you that it will break in by the 600 mile checkup (~US$350 additional out of your pocket). Get him to put that in writing with a clause that you can return it for another example if YOU find it misbehaves. (The dealer will tell you the surging and stalling is operator error.) Better yet, find an example that does not behave that way. Post-January 2001 date of manufacture units (see sticker on steering head) seem to be less affected. BMW fuel injection programming has passed version 3.0, installed using programmer software v.9.x. Some folks have had good luck changing to an R1150 injector (~$110) and drilling a couple of holes in the air intake snorkel. This may or may not be covered under warranty, depending on how informed/intelligent your dealer is and how generous BMW is feeling the day your claim arrives. Caveat emptor. BMW has not figured out this fuel injection thing 100%, yet.

Surging and Stalling Fix
by Joe M. 27-May-01

Early F650GSs (both the regular GS and Dakar version) were plagued with stalling and surging problems. The stalling typically occurred at idle or upon deceleration. The surging would generally occur between 3,500 and 4,000 RPMs. The US-spec bikes, which had more stringent emissions controls, were most prone to these problems, although ROW (rest of world) owners have reported similar problems."

"BMW has responded relatively promptly to customer complaints. First, all bikes produced after the 4th week in January, 2001, were fitted with a different fuel injector (the one that is standard of the R1200C and other models), and the BMS Compact (the engine computer) was updated with new software to work with the new injector. There have been very few reports of surging and stalling from owners of this "new production." Individuals considering the purchase of a GS should endeavor to ascertain the production date (stamped on a plate on the steering head), and buy a post January 2001 model.

"Insofar as earlier bikes are concerned, BMW has offered to update the computer under warranty, WITHOUT changing the injector. This has resulted in significant improvement for some, marginal (and nonexistent) improvement for others. Although BMW has not offered to provide all older production bikes with the new injector under warranty, many individual owners have reported that their dealers have covered such parts and labor under warranty. In any event, warranty or not, many owners have reported a dramatic improvement with the new injector and software, resulting in elimination of all surging and stalling, and a smooth running engine at all RPMs."

Kristian #562 (re-)posted:
All Oilheads use the same injector. BMW #13711342366 Bosch #0280155788. The F650GS uses Bosch #0280156026.

by Flash #412

There are two "vent" hoses attached to the tank. One is a vent and the other is an overflow drain. When you overfill your tank, it drains straight out the overflow onto the ground. Note that when you close the gas cap, the space this hose reaches is SEALED OFF from the interior of the tank. The OTHER hose is the vent hose.

The vent hose goes to a (stupid) charcoal canister. There are two other hoses connected to this canister. When the tank develops overpressure, the liquid/fumes go into the canister and are collected by the charcoal. There is a big hose that leaves the canister and goes to the air, by your right footpeg. This is for fresh air INPUT to the canister. The little tiny hose goes to the carb. The carb draws a vacuum, which sucks on the little hose, which sucks all the nasty hydrocarbons out of the canister, to be replaced by fresh air, in a limited quantity. If it got too much fresh air, the bike would run too lean. So instead of getting too much fresh air... it sucks on the tank, creating a vacuum, which makes the bike act like it is out of gas.

You take the little hose from the carb and plug it up. One handy place is the junction on top of the airbox, just behind the tank, under the seat.  You take the long hose from the tank to the canister and reroute it to the place where the hose that used to go from the canister to the footpeg went.

In this configuration, the carb doesn't suck on the inside of your tank.  And the tank can "breathe" fresh air if it wants to.

I have a canister, in a box in my garage.

by Bob#550 - 31-May-01

My '99 F650 has two vacuum lines connected to the right side of the right carburetor (looking down from a seated position). You might have to remove a plastic panel to get to these, but you can see them without removing anything.

The front vacuum line should go into the airbox, and the rear one should go to the charcoal cannister (if you have one), or it may just be plugged with a screw or something if the cannister has been removed.

I don't know what the European-spec. bikes are like in this regard.

by Shank

This is how I see the chain mess:

If you can't expose half a tooth your chain is fine. I find that chains (and I'm assuming you have the stock chain) slowly wear and then BAM, they're toast; they don't hold an adjustment, they are super floppy and you can expose at least half a tooth (kind of like titties). Also, examine the rear sprocket teeth, if they aren't even and if they measure less than 3mm at the shoulder of the tooth, the sprocket is toast and it will soon toast your chain (if it's not yet toasted).

As for the rust, my chain is rusty on the side plates, as long as that rust isn't chewing the o-rings, you are fine. As for the stickiness, about midway in chain life I wash it with kerosene. Basically I have two tubs of kerosene about one knuckle deep. I take the rear wheel off, I place the chain in tub#1 and scrub it with a toothbrush, when I've scrubbed the accumulated spooge off the chain, I then pull the chain off the front sprocket and scrub the sprocket and clean all the flung spooge and crap off the inside of the front sprocket cover, I wipe off the rubber chain guide thingy on the swing arm (usually takes some toothbrush scrubbing), wipe the rollers off and clean off the rear sprocket and chain guard. Then the second tub of kerosene is for a second rinse of the chain and a second wash of all related parts to get everything squeaky clean. Then I put it all back together, adjust slack, start the engine and while it's on the centerstand I put it in first gear and fling the kerosene (paraffin for the limeys) off the chain. Then I liberally spray Chain Wax all over it and I'm done.

A big messy job but I feel that the buildup of Chain Wax, although very protective against water and rust, keeps chain-killing grit in there as well. So a cleaning makes me feel better.  The reason I'm saying this is because you might want to try cleaning the chain. 

I think that the F, as spunky as it is, doesn't have enough torque to cause catastrophic failure of the chain, even if it's quite worn.  My chain is also "grabby" when it's cold.  But smoothes out when warm.

FITTING A CHAIN by Flash #412

If you replace the chain at the same time as the sprockets, as I assume you will, just get the standard DID 520VM 120 link x-ring chain. It doesn't cost any more for 120 links instead of the required 110 links..  Install the sprockets and then set the wheel toward the front of the adjustment range (a couple notches back from full forward). Fit the chain but MAKE SURE YOU ARE NOT OFF A HALF LINK before marking to cut it. Don't forget to leave some slack. Press a pin out and unless you screwed up, it will be right.

Some old dirt biker friends of mine told me ALWAYS fit the chain to the sprockets ON the bike. NEVER just count links and cut the chain on a bench.  I decided to learn from their hard-earned mistakes.

When you go to install a clip-type master link, you may find it difficult to press the side plate on far enough to mount the clip with the x-rings in place.  There's a trick you can use.  Take an open half link from either your old chain or the end you just cut off your new one.  Place the link on top of the new side plate with the opening that the pin went through over the pin hole in the side plate.  Use your pliers or vise grips to squeeze the pin through the side plate.  You should alternate pins a couple of times, proceeding slowly.  In three steps or so, you'll have the pins through the side plate and ready to receive the clip.

by Richard #230 (May '01)

I recently installed a new Ohlins Type III (BM 423-46DRS) rear shock on my bike. This is the type with a hydraulic pre-load adjuster and a rebound adjustment, but no remote reservoir or compression damping adjustment. I bought it from Mr. Ed's MotoAccessories. By taking advantage of their "Chain Gang Buy", I was able to purchase the shock for a total price of $570. It took me 5 hours to install (it should take you 3 hours) and I had no problems. Everything was obvious and no special tools or parts are needed. You will need a 3/8" torque wrench, an 8 inch 3/8" extension, an 8 mm 3/8 inch drive hex wrench, a selection of 3/8" drive socket wrenches and bearing grease. I used BMW No.10 grease to grease the suspension linkage needle bearings. (I did not remove the bearings, as I tend to lose small parts. I just packed more grease into the bearings.)  [Ed: You'll also need a 10mm allen wrench.]

I removed the rear wheel, but not the swing-arm. I removed all of the suspension linkages and greased all of the needle bearings, which may not be absolutely necessary, but seems like a real good idea to me. With the linkages gone, the shock just falls out of the bike, when both the shock's lower and upper mounting bolts and the small pre-load adjuster bolt located behind the cylinder on the left side of the bike are removed. I noted that my upper shock bolt did not have a washer on the left side, as shown in the service manual. The upper mounting bolt can be reached without removing the battery box, by using a hex (Allen) wrench fitting for a 3/8" drive, mounted to a long extension rod and taped in place to keep it from falling out, while it is threaded past the battery box and hoses. (Sears and hardware stores sell these (socket-type) hex wrenches for a few bucks.) Otherwise everything seems straightforward. The right linkage bolt must be removed before the left, to have enough room to be able to withdraw the left bolt. Also, the lower plastic chain roller (which I had never seen before) must be removed, before the adjacent bolt can be withdrawn from the suspension linkage. My roller looked like new, but if yours is worn, now is the time to change it, so you might want to buy a new one before starting the job.

When installing the new shock, you will need to take the aluminum Ohlins mount off of the pre-load adjuster and thread it between the right frame and the air-box. The adjuster hose gets run along the right frame rail and fastens to the front rubber charcoal canister mount, after re-installing the adjuster bracket (no problem there, as my canister has been missing for 4 years). This is for the budget shock with no compression damping, only remote pre-load and rebound. If you have the remote reservoir shock, the reservoir gets mounted here and the pre-load adjuster is installed in the stock position.

Tightening torque values are: 50 NM for the upper shock bolt and 30 NM for the lower bolt, 80 NM for the tension strut to the deflection levers (the long bolt) and 50 NM for the bolts fastening the deflection lever to the frame and for the tension strut to the deflection lever and swing arm. To summarize: The longest linkage bolt gets 80 NM, all other bolts get 50 NM, except the lower shock mount, which gets torqued to 30 NM. 

I am enclosing pictures that I took while doing the job, including a comparison of the new Ohlins and the old stock shock, the mounted adjuster and of the completed installation. [Ed: These pictures are not on this deathstar site, yet.]

Finally, I highly recommend using waterless hand cleaning "Scrubs" towels (available in hardware and paint stores, as well as through Whitehorse Press). Not only do they do a good job of removing chain oil from your hands (much better than Goop or soap), but they really work well cleaning chain oil and dirt off of the suspension parts and swing-arm. Just look at my pictures of my bike with 22,000 miles on it, after being cleaned with two of these towels.

by Flash #412

When mounting aftermarket horns, in order to reap the full benefit of their louder sound, you should use a large gage wire from the hot terminal of the battery, though a 10A fuse, up to a relay near the horns.  Also use large wire from the relay to the horns and the horns to a good, solid ground point.

I mounted the pair of Fiamms and the relay up under the fairing. The relay fits along the left side of the steering head, tucked in near the speedo cable, mounted to an existing bolt. The horns... after a lot of fitting and farting, I figured out that you can mount their brackets to the two bolts that hold that little plastic cover mounted to the bottom of the triple tree. Positioning the horns on their brackets is tricky. The trick is in getting them profiled so that they do not foul the fender at full compression. You need to mount them with the stud up, with the snails curving from back of the bike, toward the sides, to the front. You'll probably be bending the brackets a bit.

Note: BOTH of my Fiamm brackets failed. I am glad that I installed HEALTHY ground wires to each of the horns via a ring-lug at the stud. Neither was lost. One, I remounted with the stock BMW horn bracket, which is NOT available as a separate part. This actually fits better than the stock Fiamm part. The other I remounted with a bracket from a Ducati.

by Harl #380

The fork fluid is easy enough. Put the bike on the centerstand. You will have to deal with spring preload, so support the bike under the frame with a jack or from above at the handlebars. Do one side at a time, removing the cap on top, then the plug on the bottom of the fork leg. After the oil drains, replace the plug (using a new seal), pour the measured amount of oil (600cc per leg of 7 or 10wt.) into the fork, and replace the cap. The fork boots are another story. You have to remove the fork leg from the triple clamps, which also involves removing the fender, fork brace, wheel, and brakes. I put /6 BMW boots on (part no. 31 42 1 234 908) and they look sharp. 

RAG#14 Noted:  The first time I changed the fork oil, I found the caps flush with the triple tree. The tree clamp may hold the cap also as the dealers now set the cap 3mm above the tree. Of course this is of no concern for motos with lowering kits. 

[Ed: If you want to lower your bike some, take a good hard look at where the fork tubes go through the upper and lower steering head. You probably should put a jack under the bike with a bit of wood or cardboard protecting the bottom of the bike. is the parts drawing. Note that there are THREE screws numbered 3 on each side. Loosen all six of these screws several turns. Let off the jack some. If the bike doesn't drop down, raising the tubes in the steering head, you may need to GENTLY apply the tip of a screwdriver to the splits in the castings.

There are copper washers at the drain plugs and o-rings at the caps you might want to replace.]

[ed: The BMW parts fiche shows the WRONG fork. Therefore, you will get the wrong crush washers. What you WANT is copper washers 6x10 mm, part number 11 14 2 343 240. (These are the same crush washers as the one used for the coolant drain screw when you work on your water pump.) Your dealer will try to give you 31 42 2 312 710 which is 8x13 and WRONG.]

by Flash #412 is the diagram to consult.  Remove the two screws and pull off the left sidecover. The solenoid is not in the diagram (to the right of the battery).  It is attached to the cover and can be left in place. Remove the screws that hold the cover, number 4 in the picture. Pull the filter assembly out. 5 and 6 can be popped apart. Remove the foam. Clean the foam in detergent and warm water.  Unless someone has used the other kind of filter oil, that should clean it.  If it doesn't immediately work, try mineral spirits. After you get it all clean and rinsed, let it dry completely. Get some water-washable filter oil and follow the directions. Let the oil "set" completely. Reassemble in reverse order. It is pretty obvious how the foam goes back in the rack. And the assembly only goes back in the housing one way.


Remove the seat.  Remove the side covers.  Remove all the screws that secure the gas tank to the fairing.  Remove the left and right engine covers.  Remove the big bolt at the back of the tank.  Pull the fuel line off the petcock.  Pull the tank upward and note that there are a couple of vent hoses.  If you have removed your canister, one is hose short and plugged.  If you haven't, you should.  The other hose has a connector inline where you can "break" it.  Remove the tank and set it aside on top of something so that it doesn't hurt the petcock/nipple.  Remove the tank support bracket from the frame.  Loosen the hose clamps which clamp the rubber carb boots.  You might want to use a flat screwdriver to sort of pop the lip of the boot up and spray some Armor All (tm) or Son of A Gun (tm) or other rubber treatment/lubricant in there to get the rubber unstuck from the metal and lubricated all around the lip.  Repeat for all the rest.  Wiggle the rubber, pull on the carbs and cuss a lot until they are free.  Pull them out.  "Install in reverse order."

by Flash #412

A while back, Doug #317 said, "The part number for the Kimpex heated grips is 994398. I didn't find it on the web
site but called and they confirmed it, Accessory Warehouse  800/241-2222.   I ordered some at a total of around $35. A couple of the local "missing links" around here are quite satisfied with theirs.  These work even better than the $300 kind and have a three way switch, hi-off-low."

I've done this twice. The first time, I wired them from the battery via a fuse. The second time, I was back in the USA and dug around in my piles of crap and found a mating connector for the factory installed, factory-hot-grip connector up in the fairing. I ran off there, via a fuse. 

I drilled a hole in the dash, after checking from the back that it would fit where I wanted it to go. I picked up a rubber cover for standard toggle switches at an electronic parts place for about $1, making it completely waterproof. I have a black, rubber-covered, toggle switch on the dash, just below the roundel. Hi-Off-Lo. No indication of what it is. 

The grips that I got both times were too long for the F. The first time, I cut off JUST the closed ends. When I went to install them, I had to use some washers for bar-end spacers. To be on the safe side, I got some longer bar-end bolts, too. 

The second time, I cut the grips to fit, which unfortunately cut the heater wire (in each grip), too. I soldered in a small patch wire which I "sealed" into place with some epoxy and then covered (just the end of the grip) with tape. 

They work GREAT. 

Just before I bought the first set in France, I was all prepared to make my own. Take a look on my website for how I was going to make them, posted by an Australian. Note: I did NOT follow this plan. And so I can't say from personal experience that it'll work. That info is posted at 


Revue Moto Technique No.96 Janvier/Fevrier 1995 published by E.T.A.I. 96 rue de Paris, 92100 Boulogne Billancourt FRANCE.  The sales department is at Librarie TRAME, 62 bd Jean-Jaures 92100 Boulogne Billancourt FRANCE. There is some small print that says E.T.A.I. 11/94 and CIP 961 on or near the spine. I recall that they cost about FFr 100-120, depending on where you get them.

This is a paperback book series that comes out every other month. Each issue covers several bikes. Issue 96 includes Yamaha DT125R '93-'95, DT125RE '89-'95 and TDR125 '93-'95 as well as BMW F650 '94-'95.

Since there were essentially no changes between '94 and '00 or between the Funduro and the ST other than styling and some minor stuff, the manual is comprehensive, if you can find one and if you can deal with French.

Not only does it have the requisite tear down, but features some very interesting photographs and drawings. There is a photo of women building motors in the Rotax engine assembly plant and a few of the bikes being assembled in the Aprilia plant. Three are also some styling exercise pencil sketches.

They tear the motor completely apart, as is demonstrated by some photos which are clearly NOT from the factory manual. There is an original schematic (which has several errors in it). There is a maintenance chart which refers you to a page where each item is detailed in the manner of FORMER BMW manuals. Some BMW parts layouts are included. There is a mechanical drawing detailing how to make the crank-holder bolt and another of the alternator puller set. (Note: BMW gets about seventy cents U.S. for the bolt and less than US$20 for the puller set. These are the only F650-unique tools required to maintain this machine.) It has some good trouble-shooting tips for the electrics. Unlike the Official BMW manual, this is easy to use with things like torque specs in-line with the text telling you to do whatever it is.

In short, Moto Revue is top-notch, right up there (maybe even above) Haynes. I keep it handy even though I now have the BMW manual, too.

Shortly after posing this, Jean #636 noted that this manual is no longer in print. C'est la vie!

There is, however, a lower cost alternative to the US$110 BMW workshop manual.  Get the micro-fiche version of the same manual for about $30 or so.  You can print pages as you need them in most public or university libraries.  Many large corporations also have microfiche reader/printers.  If you're lucky enough to have that as a perk, go for it.

PUKING PETROL by Flash #412

Last night I stopped and filled up 0.8 miles from home. I was careful not to overfill. NO gas escaped into the "well" below the metal cap. I parked the bike in the garage. At about 4AM my wife woke me up because she smelled gas. There was a large puddle below my bike. I put a coffee can under the hose and mopped up the puddle. Thinking to improve the situation, I put the bike on the centerstand. When I did, another table spoon or more poured out. In the morning, there was almost an INCH of gas in the coffee can. I pulled the bike outside and parked it on the centerstand while I drank my coffee. When I went to leave, a half hour later, there was about a two foot diameter wet spot on the concrete under the bike. It was hard as hell to start. I stalled it at the bottom of the driveway. I happened to look back
and see a trail of drips from the big wet to where I was. I rode it about eight miles and stopped just to check things out. No more drip.

Additional info... I've smelled gas in the garage every night this week, even when parked with more than 100 miles on the tank.  The temps lately have not been extreme. I think there was not such a great differential between the temp of gas in an underground tank and the temp last night. If anything, the air was cooler.

Subject: Pukin' Petrol (The Answer!)

When you remove the float bowl, there is a plastic assembly which consists of the floats and a holder. The float needle clips on to the floats. There is an o-ring on holder. This o-ring had a positive feel to it when I removed and reinstalled the holder. With the assembly removed, there is a bronze piece which is (or contains) the SEAT. This bronze piece also has an o-ring. However, BOTH of the seats just plain fell out when I turned the carbs upside down. I figured that if the o-ring did not have enough interference to hold the thing in, then it would not do much of a job keeping gas from getting by. I replaced the o-rings with some slightly larger (non-metric) standard ones I had in an o-ring assortment box which fit better than the ones I took out.

After putting it all back together, it started right up like it's supposed to, full choke & zero throttle. I rode around the block. When I got back, I put it on the sidestand and a few drops of gas came out one of the hoses on the opposite side from where it HAD been leaking. Being an optimist, I put a coffee can under there, turned the petcock off and left it overnight. All was well this morning.

BTW, I also installed the fuel filter while I was at it. There are four carb screws, which I replaced with allens. They are 5M0.8 x 12. But if you try to use ones that are too long, they won't go in the front holes, only the rear ones. 


An external snap ring LOOKS like the one in the pre-1997 shop manual. I can't recall if it looks like the one in the shop manual I have or not. You CAN NOT SEE it well enough in the parts manual to tell WHAT it should be. 

Basically, internal and external snap-rings are both C-shaped with "fat" sections near both open ends of the C with a hole in those sections for the snap-ring pliers. INTERNAL snap rings are very nearly perfectly round on their OUTSIDE with the swollen bits facing in. They are intended to fit into a groove in a bore. EXTERNAL snap-rings are very nearly perfectly round on the INSIDE with the swollen bits facing out. These are designed to fit in a groove on a SHAFT.

The output SHAFT on which the sprocket fits is... a SHAFT (duh). Therefore it should have an EXTERNAL snap ring. Fitting an internal snap ring means that the retaining ring only actually touches the shaft in three places, two ends and the middle of the C. Since the two ends are quite close together, the ring fits in the groove in essentially two place. Using an EXTERNAL snap ring (like they should have) would mean that there is retainer-in-groove for about 350 degrees of the shaft.

I was horrified when I found that there was an internal snap ring on my bike in France. I ordered a new snap ring. I was even MORE horrified to find that it, too was the wrong type. I added snap ring pliers to my tool kit the moment I got home.

If someone gets hurt from one of these coming off, BMW *IS* going to have to pay them a WHOLE lot of money over this. This is criminal negligence.  The entire power output of the motor goes past a WRONGLY SPECIFIED common retainer. How come it is RIGHT in the picture, yet installed wrong at the factory and delivered wrong from spare parts stores? (My very first post to the Chain Gang was over this issue.)

If you want an external snap-ring, measure the shaft outside diameter and the thickness of the ring you have. Go to any industrial parts house where you would go to get bearings and seals. Tell them you want the equivalent snap-ring thickness for an external snap-ring for a shaft of  X-mm diameter, not counting the groove. They should be able to look it up in the Machinist's Handbook. It is a STANDARD part (mis-specified by BMW).

WATER PUMP PARTS by Gary in Ohio
These were the parts for my '97 F:
impeller packaged with 2 rubber seals 11 51 2 343 451
o-ring 11 51 2 343 129
pin (solid) 11 51 2 343 127
clampbush (roll pin) 11 51 2 343 123
thrust washer 11 51 2 343 125

First off print out a copy of the water pump assembly. Remove the fuel tank to get access to the radiator. Check the radiator cap for grunge and clean it. Locate the water pump cover which is on the left side of the engine towards the front. Remove the lower of the three allen bolts and have a bucket ready. Put your bike on its side stand to empty some more coolant. Remove the remaining bolts on the water pump cover. The impeller is behind it. Drain your oil and while it is draining, remove the two bolts holding the starter and let it hang. Remove the clutch cable lever and shift lever. Get a magic marker to mark the position for re-install. Remove the engine cover bolts and note location (different sizes). Gently coax the engine cover off and watch out of the shift lever seal.  Now you see the innerds but what you are after is on the engine cover. Remove the impeller by knocking out the locking pin with a small punch. Gently tap out the impeller shaft through the engine cover. Remove the seals. I reused my pinion gear and washer and you may do the same. The new parts installed were a new impeller and shaft along with the seals. When replacing the seals note the placement. BE PATIENT when putting the engine cover back on and watch out for proper alignment being the shift lever and the clutch release shaft. Button it up and fill yer fluids and pat yourself on the back. Go out for a ride.  [Ed: Any automotive non-silicate, non-nitrite antifreeze mixed 50:50 with water is fine, and lots cheaper than BMW or Honda juice.]


With the wheel off the ground, grab the tire with hands opposite each other. If the axle is pointing at your navel, push one hand away and pull the other toward you, then reverse the motion. If you feel play, the bearings are shot.

Or, with the wheel off the bike, stick your finger in the axle hole and rotate. If you feel anything "crunchy," the bearings are shot. Do both sides of the wheel and also the sprocket carrier.  

Replacement bearings cost about US$5 each at any bearing supply house.  These are standard industrial supply parts.  Why pay a dealer 5X the price for the same (or even lesser quality) parts? The part numbers are listed in the F650 Maintenance Log.


Remove the line from the bottom of your airbox to the right exhaust header. This is the steel/rubber/steel piece that follows the right header pipe rearward. Plug the airbox (better yet, pull the air filter and pull out the exhaust re-circulation valve), cut the pipe behind the exhaust end connection, and replace it on the threaded piece it came off of with a 3/8" ball bearing inside it. That ended my backfiring.  [Ed: Some folks cure backfiring by turning up the idle slightly.  This is the brass knob on the end of the black flexible thing hanging out the bottom of the carb set.  Other folks have had good luck adjusting the idle mixture screws.]

One other alternative might be an exhaust gasket...

97 F650 BACKFIRING - Bcwill - 01-Jun-01

Recently went to replace gasket where header pipe meets cylinder head. After pulling left header pipe I found culprit of noise, blown out header pipe to colletor gasket. This was a corragated sleeve that failed under the clamp. Replacement gasket is no longer corregated. Added bonus was the commonly reported backfiring problem, I thought I had to live with, is now completely gone. Try this $11.00 fix if your bike is backfiring.


I installed it myself and took it out myself. It's not rocket science, but you need to be a little bit mechanically minded AND have a couple of BMW Tools.

1. Tools: -You will need 2-3 Allen Keys (All In Toolkit) -Flywheel Puller (US$15 from Team Pami) -Bolt to Hold Engine at Top Dead Centre (US$5 from Team Pami) -Oil -Torch -Torque Wrench and Large Socket Sorry I cannot remember the Allen Key/Socket sizes. -Possibly a new Flywheel Cover Gasket -Small Blowtorch -Loctite -Large Drain Pan or Cloths for under Crankcase -Crush washer for TDC Bolt - A piece of wire or plastic zip tie -Patience (Yes it is a tool :-) ) -The Woodruff Key - It took a while to get the $US10 Key out of Ron Woods (Not a big ticket Item). I have a couple spare, if anyone wants one, for 5$.

[Ed: the crank-holder tool/bolt costs less than US$1 at a dealer in the USA.]

Some of you may disagree with the order I did things in, but I did it out of Laziness and not wanting to drain my (just changed) oil. It was OK, just a little messy. Those who have to change the oil or want to do it the right way can ran the oil from Both Reservoir and Sump, but that's another story.


2. Installing the Bolt to Lock the Engine at TDC. a. Remove one Spark Plug. Reasons are to both measure the TDC and if you don't you will get massive compression and won't be able to rotate the crank. b. On the LEFT Side of the Engine Underneath the water pump is a Stainless Aluminium Bolt with an Allen Head. It leads into the Crankcase. In order (I'm LAZY) to NOT have to drain the oil first, I lent the bike over to the Right against a wall (While on Centrestand i.e. One leg so tie it back and make sure it is STABLE), and removed the bolt which has a crush washer under it which should be replaced after about 2-3 uses. The leaning will (mostly) prevent oil falling out the hole. c. Now what I did the first time is to engage first gear and rotate the Crank using the back wheel. (Later I will explain how this can be more easily done using a Spanner on the Flywheel nut, which is what you can do IF you've removed the oil.!) d. Put a small screwdriver or steel pin into the Spark Plug hole (You will need help here from (Girlfriend / Wife / Son / Mate here) and rotate the rear wheel until you feel the piston comes up all the way to the top and I found just a fraction over. over. Those of you with 97 onwards could also put a spanner on the countershaft nut and do it that way, but do it clockwise.! e. Now you will need to take your torch and shine it in the hole where you took the Stainless Allen bolt out of. You should see one of the crank weights with a groove in it. If you're not sure get your helper to rotate the wheel SLOWLY while you look into the hole with a torch and WATCH the Crank go around. The weight will disappear at Bottom DC and reappear, so watch carefully. As it nears TDC go very slowly and you should see the groove. f. When you do, and ONLY when you do screw in and tighten up the TDC bolt. This locks the Crank at TDC.

Note that if you elected to Drain the oil first, you can rotate the Flywheel with considerably less effort with a Spanner on the Flywheel Nut after you removed the Flywheel casing cover. TDC is about a finger or small thumb width between the Ignition Pickup at the top of the engine and the small rectangular steel plate that induces the current for the spark as it passes the pickup. The Rectangular plate is one finger FORWARD of the pickup, i.e. toward the front of the bike. If you elect to drain the oil first do step 3 then step 2. (Make sure you're in Neutral to do this).

3. Removing the Flywheel cover (Right side of Engine). If you didn't drain the oil first, lean the bike well to the LEFT and stabilise as per 2(b) above. a. You will need to first Remove the Countershaft (Front) Plastic Sprocket Cover (3 x Allen Bolts) b. Then undo all the (about 8-9) Allen Bolts from the flywheel cover housing. The upper two are attached to a plate covering the wires to the pickup. c. Now, there is quite a bit of magnetic pull on the cover, so it won't come off really easily. If you want to save the Gasket (and you can) you will need to be very gentle and ease the cover off evenly all around. d. WATCH OUT you do not LOSE the washer which sits on the Toothwheelshaft for the Toothwheel that sits BETWEEN the Starter Toothwheel and the Flywheel Toothwheel. It tends to stick (Due to surface tension in oil) to the inside of the Flywheel cover and then drop onto the floor. There will be some oil spillage. e. Open up the cover to the left like a door and take a piece of wire or your zip tie and tie through one of the bolt holes, onto the frame. Your seat should already have been removed.... :-). That will hold it out of your way. f. You will see the flywheel, the starter toothwheel and the toothwheel in between.

4. Removing the flywheel. a. Now take your cloth and WIPE all surfaces around the Flywheel nut so you don't asphyxiate yourself, then take the blowtorch, heating tool and heat the Flywheel nut. b. ASSUMING you were successful with the TDC bolt, you can now remove this nut. If you haven't yet installed the TDC bolt, and you drained the oil, INSTALL THIS NOW, using a spanner on the Flywheel nut as described above to turn the crank. (Make sure you're in Neutral to do this) c. OK, when the nut is removed, screw on the Special BMW Flywheel Puller Tool and screw it over the flywheel, then tighten up the centrebolt until the old Loctite "Cracks". d. Again there is a fair bit of Magnetic pull, but you can now ease off the flywheel to reveal, Lo & behold, Tada, the Pathetic little woodruff key that you've spent all this effort to get to. It should be at or close to the top of the shaft if you got TDC right. e. Using a PLASTIC or wooden drive or gentle screwdriver action tap the front and back of the key until it pivots and loosens in its groove, then gently tap it out. f. Equally gently tap in the new key with the CUT OUT SLOT facing the REAR of the bike. This will allow the flywheel to rotate a bit more clockwise effectively giving you the timing advance.

5. Replacing the Flywheel. a. This was the Hardest part for me and boy did I struggle the first time. Then my Girlfriend came out and it was on in 30 seconds (The flywheel :-)). b. Here's what you do. CLEAN VERY thoroughly the shaft and flywheel (inside) and coat the shaft with the Loctite. c. Feed the Flywheel gently onto the shaft making sure you line up the groove in the flywheel to the woodruff key. It will NOT go onto the flange on the flywheelToothhweel straight away. If it does, Go Buy yourself a lottery ticket and Propose to your Girlfriend, Remarry your wife, whatever. Do not force it and do not at this stage rotate the partially placed flywheel on the shaft as you will damage the woodruff key. d. What you need to do is actually rotate the whole flywheel and shaft. To do this you need to YES, you guessed it, remove the TDC Bolt or at least unscrew it partially. Boy sure looks like removing the oil first is a good idea now doesn't it, leaning the back and forward is a Royal PITA. e. OK having released the Crank to rotate freely and assuming your one Spark Plug is still out, engage Gear and get your helper to Rotate the Crank Clockwise while you push gently, the flywheel back onto the shaft and over the flange. It only requires a small rotation but it requires rotation. It'll just pop on. f. Now when it does before you get all excited and do up the nut, you will have to re-engage the TDC Bolt. So look at Step 2. again. g. THEN Rotate the flywheel clockwise on the shaft so that the groove comes up against the cut-out in the new key. h. Put some loctite on the threads of the shaft and replace the Nut, Torque to Spec.

6. Replacing the Cover. a. Wipe all surfaces clean and if you bought a new Gasket smear it with oil first, both surfaces. b. Check the washer from 3(d) above is in place, the rubber surround to the ignition pickup wires are in place and gently ease the cover over the flywheel. It will try to pull on strongly due to the magnet. Be GENTLE or you will rip the Gasket. c. Do up the Allen bolts going around the cover doing each a bit at a time, then torque. Don't forget to put the top plate back (2 Allen Bolts). d. Replace the Sprocket Cover. e. DON'T FORGET to REMOVE THE TDC Bolt and reinstall the Stainless Plug Bolt. Put a new crush washer one, they are pittance cost wise, but if you can't get one you can use the old one. f. Crank her up. It will be leaner so check out this site to make sure your plugs are a good colour and not overheating:

OK now you've read all this garbage, TEAM-PAMI in Germany, to whom I have no affiliation (I'm in Hong Kong btw) did some Dyno runs with the Ron Woods Key and reckon the stock. Saying that I felt it DID give me more oomph low down, but it was running so lean when I chopped the plugs I'm sure I could see little bits of Aluminium on the plugs from the head. Not a good sign. I could definitely have richened the mixture a bit as I was lean from my Staintune and Airbox Organ pipe Cut-out, but in the end I did all the above once more and replaced the original key as I thought about Team-Pamis comments. I think if you did it like Ron Woods did maybe one of those Ultra$$$ Nikasil Pistons would be in order :-)

Cheers and Regards and a Big Thanks to Richard230 (who truly is helpful person), Harl, Fede, Craig, Todd, Flash, Walter and Mark58 the latter who wrote the following oh so true statement:

"I don't know your riding background, but if you're like the majority of folks, you'd be far better off taking an advanced riding school than spending a couple mortgage payments worth on aftermarket exhausts and trick performance parts. Most folks don't use half of what they've already got. I realize this is heresy and that there's a time-honored tradition of fiddling with your ride to personalize it, but a lot of times those bikes that have been "upgraded" are really messed up. If you know what you're doing, then a freer flowing pipe, jet kit, airbox mods and so forth can eke out a few more HP and smooth things out a bit, but the dollar spent to HP gained ratio is pretty high and the effect lasts until you get tired of your current bike. Good riding instruction lasts forever. You could also spend the money on good riding apparel. Your call."


This is a simple job and can be done with just two of the tools in the tool kit.  Remove the black plastic engine covers from either side. There is a screw facing DOWN that attaches them to the plastic piece at the radiator. Remove the screws between the tank and the fairing on each side. Put a jacket or heavy towel on the front fender to protect it in case you drop the fairing. Remove the four screws holding the windshield. Remove the windshield and the black plastic piece under it. Don't lose the rubber nuts, which are a press fit. There were four screws exposed when you removed the black cover piece. Only the two facing directly left and right are holding the fairing at this point. You leave the other two in place. When you have the fairing lose, pull forward a bit and wiggle it to get it loose from the tank. Unplug the connector from the back of the headlight bulb and pull the parking light rubber out of its socket in the headlight. Unhook the turn signals and set the fairing aside.

To reassemble is slightly more time consuming than disassembly. Be sure to plug all the lights back in before you start replacing any screws. Pay careful attention that you have all the tabs and slots happily mated between the tank and fairing before you start with the myriad of screws. Those two screws at the top which you removed last should go in first. They'll support the mess while you dink with the tabs.

Now... the trick... before you insert a screw, stick the allen wrench in the hole and make sure every thing is aligned. Work slowly and patiently. Insert ALL of the tank screws a couple of turns and THEN tighten them down. Do not over-tighten. The rest is simple after that, except maybe for those rubber nuts that hold the windscreen.  What I do is spit on one of them and stick it through the black plastic thing and then through the fairing.  Repeat until all four are in place.  Then CAREFULLY put the windscreen up against the rubber nuts and carefully insert a screw through the plastic.  Screw in until you're confident that the screw has contacted the brass nut inside the rubber cover.  Get them all started before you tighten them.  Do NOT over-tighten because the nuts will pop out and you'll have to start all over again.

FLASH'S BOOK by Claude #312 - Date: 19-Dec-00

Given that we see Flash on the list every day he is not touring the world for his job, and also the good stuff on his web site, I ordered his book to see what a lot of his writing would be like. The answer is it was very good.

As Mole really said, "Nothing is half so much worth doing as simply messing around with motorcycles," and Flash has done a lot of it in some very interesting ways. Side cars, old BMWs, F650 in France, buying and selling parts in huge quantities, etc, etc. Things we all wish we had the time to do.

Anyway, get his book; its a good read. Order it from his web site and save a buck or two. He even spelled my name correctly when he autographed it.

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