F650 Engine Misc FAQ

compiled & edited by Kristian #562
Please read the Disclaimer before attempting any work in this FAQ.
Last Updated: 15 June 2007, by Winter #1935

• Introduction
• Engine Failures etc
  • Strange Engine Noises?
  • Complete New Engine?
  • Engine Weight?
  • Catastrophic engine failure
  • Catastrophic engine failure - Part 2
  • Engine Rebuild?
  • Blown Cam Cover Gasket?
• Rod Bearings Failure
• Snapped Bolts
  • Method 1: Drilling (cylinder head to lower engine bolts)
  • Method 2: Using EZ Outs (other bolts)
  • Can I ride my bike without a valve cover bolt?
• Misc Questions
  • Ring Gaps
  • Ported and Polished Intakes
  • Will a GS engine fit in an ST frame?
  • Compression Release Mechanism (What is this strange thing on the end of my camshaft?)
  • The paint on my engine is bubbling?
  • Is the Rotax engine interfering or non-interfering?
  • Where do I find the engine number?
  • What is Desmodromic valve actuation?
  • Gouge in cylinder-head?
  • Valve Guides
  • Performance Improvements
  • Increased Alternator Output

Also see the following FAQs:

• Strange Noises FAQ
• Classic Engine Removal FAQ
• Compression Testing FAQ
• Classic Hard Starting / Poor Running FAQ
• GS Hard Starting / Poor Running FAQ
• Rotax 655 Troubleshooting FAQ
• Counter Balance (c/b) Seal Failure FAQ
• Cylinder Cleaning FAQ
• F650 History and Differences FAQ for information on engine performance, and other motorcycles using a Rotax 654 / 655 based engine.

It is highly recommended you get the second DVD, as this contains loads of hints and tips on how to drop the engine out of the frame, and pull the whole thing apart (if you need to do that of course).

Q. Knocking engine, melting plastic.

Yesterday, I noticed that there was a knocking when in neutral, clutch engaged. Very scary. Moderate knocking, and I could feel it in the handlebar. Maybe from engine, but I think transmission, since it happens only with clutch engaged. I opened the clutch, because I was in there two weeks, 400km, ago to extract a broken clutch spring screw (which I had broken myself). I couldn't see anything out of order, inspected all the friction plates and clutch plates, all seemed well and in spec except one friction plate had chips in ten of the friction bumps, and I could smell burned oil when taking off the cover. When reassembled, the knocking was present but much diminished when I started up.

Went for a five minute ride to visit a friend, by which time the knock had reasserted itself (when in neutral, clutch engaged). Further, when I got home after only five minutes ride, the right engine cover was melted where it passes nearest the exhaust pipe.

Other recent work includes going to smallest shims on intake ports, so that one is now in spec and the other is almost in spec. They had been way out for a 12000km. Inspection reveals that the tachometer boot over the tachometer connector on top of the clutch is wet with oil, though it may have been before; the oil tank line from the top of the engine case near the oil pressure switch is wet with oil for a few centimetres, though it may have been before; there is a minor leak in the oil seal at the countershaft, which has been there for 7000km. There is no detectable knocking when riding or when the clutch is disengaged. By clutch engaged, I mean the clutch, not the lever. That is, clutch engaged = engine connected to transmission, the lever is at rest. Idles at 1350 cold, 1500 warm. Just to cover the point properly, I went out now and tried gradually raising it to 1600 (engine is cold right now), and the knocking merely got faster, not in any way diminished. I forgot to mention that there is a ticking, but it's always been there. Sounds like valves, but I've read somewhere that it's the chain, and it's normal on the F. In my investigation this morning, I had the clutch fully open. Inspected all the plates, found on friction plate with small chunks taken out of ten bumps (little friction pads on the plate). Small enough pieces to have been filtered out, I believe. Otherwise, all parts appeared to be okay and torqued up properly. I did not remove the clutch nut. Is it worth removing the clutch nut to look around behind (real PITA, that clutch nut)? Do you know how far can I go without pulling the engine out? Aleksander in Dubai 98ST

• "I noticed that there was a knocking when in neutral, clutch engaged. Very scary. Moderate knocking, and I could feel it in the handlebar." I am going to assume that your idle is high enough so that it isn't the compression release knocking. Try turning you idle up to about 1500rpm and see if the knocking goes away. Flash #412
• When you say "engaged," do you mean with the lever PULLED or at rest? With the lever pulled, the clutch is actually disengaged. If it makes the noise with the lever PULLED, that's classic throw-out bearing noise. Since you were in there 400km ago, I bet you got sand or something in the throw-out bearing. That's number 13 on parts drawing 21_0090, BMW part number 21-21-2-343-173. Though I suspect that you could buy a 15 x 32 x 9 mm grooved ball bearing just about anywhere for less money. See the Clutch Misc Probs FAQ
• If there is something wrong in your transmission, it *should* make the noise when you are rolling, too. Try this... find a long downhill, put the bike in neutral and with the engine OFF, coast down the hill. Do you hear the noise? If so, it is in the transmission for sure. You might also try this... with the motor OFF, and the clutch Disengaged (lever pulled to the handlebar), coast down the hill while shifting into various gears. The point of this exercise is to see if the noise gets better or worse in any given gear, even though the clutch is disengaged. If you don't hear any noises in any of these exercises, then your problem is probably in your motor, not your transmission. Actually, fixing either one is about the same amount of work since you need to drop the motor and split the cases to get at both of them. I intend to do a FAQ on splitting the cases and fixing the trans the next time I split the cases. And I'll likely do the one on putting the motor BACK in the frame then, too. Many of the photos in this write-up are Kristian's photos. His Classic F650 was red. Flash #412
• There's only one other guy, I know of whose Bearing went Bad. MarconeK from Malta would you believe. But it whined. It didn't knock. Kristian#562
• Melted cover: Last week I had to lay the bike down in some very soft sand (or do a painful splits). Took a couple minutes to get footing to raise it. I suspect that's when the engine cover got melted, and I just didn't notice. Knock: I did another sound check, like this: bike on center stand, engine idling. Clutch engaged in neutral, first, second, engine idling in each. The knock was present in all cases, at the same rate and intensity. Couldn't do third and up due to safety concerns. Next, I put back into neutral, stopped the wheel, and used a screwdriver as stethoscope at the valve cover, the head, crankcase, and the clutch/transmission, both sides in each case. Noise detectable in all places except the crankcase. Noise was faint in transmission/clutch, moderate at head, and loud at valve cover. Conclusion: valve job. Ticking also comes from same area, and I will see what happens after the valve job. Mark: I did soak all plates in oil before reassembly. I did feel the clutch release bearing and checked the snap ring, and all seems well. I'm aware the snap ring can look like it's in when it's not, so I did look carefully at it. I read the rod bearing FAQ carefully, and it does not seem to describe my problem, though I will be ripping apart my oil filters henceforward. Thanks all for thinking about my problem and providing the valued input. I'm ordering a valve package for each inlet. You may recall that the inlets were less than zero for several thousand kms. Getting lifter (bucket), spring, collet, retainer, washer, oil seal, and seat, for each. Will report back if it solves the noise, and in the meantime driving extra gently.

by Steve #417, Richard #230 and Kristian #562, June '02

If all else Fails does BMW Supply Complete New Engines ...?

A: Sure they do.

Are you crazy?

Actually, there is such a thing as a Complete New Engine: It is Part Number 11 00 2 343 231, it is listed as 650ccm and retails for US$5190.00. It is a valid part number.

Caution this is for the classic and not the GS.

The motor along with the carbs weighs something like 85 lbs.

Here is what it looks like:

YMMV.

• When I turned off the teevee and said to the Wolverine, "I hafta go weigh my motor." she arched an eyebrow and asked, "Is that a euphemism for something?" The motor, with carbs attached, no exhaust bits, no countershaft sprocket, weighs about 97 pounds. Flash 412 (CO)

My engine locked up on the highway, and it look really bad. As it look like I'm going to have to trash the bike I'd like to understand what could have hapenned, so I'm calling to the expertise of this forum for advices. First of all, my bike: It's a blue '97 F650ST. I bought it used two years ago, with 10k kilometers. Since then I've added 30k Kilometers without any problem whatsoever. The 10k, 20k, 30k and 40k maintenance were done by a reputable dealer near Paris. This bike has been trouble free, the only things I had to change were two rear tires (one used, one punctured), one front tire, the chain and sprockets (twice) and a battery.

The friday before last I brought my bike to my dealer for the 40k maintenance. They changed everything, all the fluids, brake pads and so on. It hurts: 430 euros... But I got a new bike back, with smooth controls and perfect driving. I drove it home. Mileage at that point, 40360 Kms. This friday I took the bike to go to a family reunion. What was supposed to be a simple 2 hours drive turned into a nightmare. After and hour and a half and something like 160 kilometers I stopped at a gas station. I refilled, with the usual 95 octane version, and spend some time tightening up the damn right hand mirror. Total stop time, around 20, 25 minutes.

I then restarted and drove another 30 kilometers. At a steady 130/140 Km/h. And then sudently, without a warning, my rear wheel locked up. After a chilling ride, rear wheel sliding left and right I was able to finish onto the shoulder. In retrospect I should have pulled the clutch, to regain a rolling rear wheel, but to be honest at that point I was thinking the less stuff I was touching the better!

First inspection of the bike showed water everywhere, and pieces of shaved metal all over the place as well. Not good... After freezing for a while on the side of the road (yeah, it was cold, 5 celcius degrees out) the bike was towed to the nearest dealer, and he looked at it today:

• There is a hole in the cylinder, behind the starter. The cylinder is cracked in two other places as well.
• The lower engine block is also torn near the hole, something seems to have hit it from the inside, it doesn't look like it could be repaired.
• After opening the valve cover, the valves and camshaft look good, there was apparently no mistake done by the dealer when looking at/cleaning the valves.
• The gas I filled up is green, and smell like regular gas, not gasoil.
• There is plenty of oil, and there was water in there before it got spilled all over the highway

In order to understand what could have hapenned, and potentially quote me a price for repairs, they need to open the engine completely, remove the cylinder, and see which parts need a replacement. At this point it doesn't look like the dealer did any mistake and it's already looking really expensive, read it will cost more than the price of the bike...

So, what is your best guess? What could have happened? Anybody know of a good engine I can buy? Anybody interested in a bike for parts :^( ? James, Paris

• Ouch... that does not sound like a very pleasant experience. Glad you got out of it still in one piece though. I know something like that would scare the crap out of me.. I hope you can find a used engine, 'cause from your description I'd say this one's gonna be expen$ive to repair. Please keep us posted on what the techs find out if you do let them open her up? veggie_deluxe
• From your description, you have probably had one of several things happen. A conrod small end bearing failure or piston failure, resulting in fragments of the piston jamming in the crankcase and getting forced out by a still rotating crankshaft/conrod. Total siezure of the piston, in the cylinder bore due to coolant loss and conrod has broken at the small end then wreaked havoc in the lower cylinder area. It could have also pulled the small end pin etc completely out the bottom of the siezed piston. Broken crankshaft at the big end crank pin. With most of these thngs, you should have either felt vibration and/or heard mechanical noise. Either way, I am sorry...but it does not sound too good....... jack
• Wow, pretty harrowing. Sorry to hear about this. Are you sure that the engine had sufficient oil? A single at hwy speed is a very busy thing. stuflinn
• Ouch, very nasty. On the marginally brighter side, in parts motorcycles are worth several times (4->6x) what they are whole, so if it's in generally reasonable nick a breaker might well be interested. Forks, frames swing-arms, wheels, plastics, brake calipers, engines, exhausts etc are all in demand. It might be as cheap to sell the remains to a breaker and buy another 2nd hand bike whole rather than trying to buy another engine. There are usually adverts at the back of motorcycle magazines. Mr Precision
• Was the water pump the original one? The water pump seals might have died allowing the coolant to be sucked into the oil which caused a big end failure causing it to throw a rod through the crankcase. Were I you, I wouldn't even mess with the diagnosis. I'd look for a wreck with a good motor, drop it in your frame and be done with it. You might be able to get some money for your motor bits or save them for spares. Flash 412 (CO)

First of all the bike is back on the road. I bought a used engine from a used parts place in Alsace for 525 euros. The engine is one year older than my bike, with 52000 kilometers on it. The guy had a trip planned to the Paris suburbs so he delivered the engine not to far away from my place. The day before I had brought the bike back from Troyes using a friend's trailer and car combination (Thanks Christophe!). All was left to do was to take the whole bike apart to swap the two engines.

It took me a while to get everything off and on as it was a first for me, but with adequate documentation (Moto Revue Technique) anything is possible. the two engines are somewhat identical except for two parts: the way to put the output sprocket and the sensor for the neutral.

A week or so ago I got to the point where everything was mounted back, but when I pressed the starter all I heard was a loud crunch... After a frightened check it turned out that when the engine blew something must have been thrown with great force on the starter as one of the magnet inside it had crumbled into multiple pieces. Well, nothing than a call to the used place can't solve. 70 euros and two days later the starter was there, I plugged it in, and on the third try the engine started.

The bike smoked a lot, but after 10 minutes idling (and me checking everything) the smoke subsided. I took the bike for a ride, and after 35 kilometrers brought it back. I've put 200 kilometers on it so far, and all seems well, minus a couple of oil leaks I have to track down.

What about the old engine you ask? Well, I opened it today. Tell me your thoughts, the pictures are here. I stopped just before opening the oil pumps, I figured if one of them failed it could have been the cause. And so far, the upper pump turns, but the lower one seems to be locked... I'll see to it tomorrow. James Bond

• My suggestion is, the piston started to disintegrate with the skirt breaking off on 1 side, that piece of metal would have fell down to the bottom of the cylinder and been pounded by the crank and conrod, the piston would have alo then tilted in the bore due to the missing skirt, from there on it just got worse.The bore shows no sign of a siezure of the piston (that I can see) The piston simply failed and the self destruction continued from that.

  Should you have been doing low RPM's the motor probably would have locked up and stopped dead, with minimal damage. By the look of the damage, you must have been riding at highway speeds when it carked it. Glad you have it fixed, you may salvage a few pieces from that dead engine :-) jack

First of all a general view of the damage, right behind the starter.	You can see that the cylinder is all cracked...	...in multiple places	note also that the carter(Crankcase) below is also touched, at this little pin is out.
To open everything, I stated by the top, removing the cam cover.	Then removing the cams. So far everything looks okay.	Well, removing the head shows that something actually hit it, damaging the valves pretty badly	Look, no piston! Where did the piston go? This is what I saw when I opened the head...
Turns out the piston has been reduced to little chunks of metal. See it down there?	I fished out this little piece and put it on the haed to give you an idea of size.	Let's look at the cylinder now, it's cracked all the way. I had to hold it together to take those pictures as the front part just fall appart. This picture is from the top...	...and this one from the back of the engine, looking forward.
It all dropped on the floor when I stopped holding it together.	nice hole huh?	Removing the cylinder, well, what's left of it.	A look inside the engine. See all those piston chunks in there?
They're everywhere...	I opened the side of the engine, to see if something stuck on the distribution chain could have caused this	Well, no. This is actually an area of the engine without metal pieces all over it

• You could buy a compression tester for $10 and do your own test to see how the engine is. The symptoms sound authentic. Perhaps you could do a valve adjustment and see if that helped the compression. It would be a lot cheaper to install and remove the head yourself and take it to a machine shop for the actual rebuild. Since they refunded your money they seem pretty honest. I would tend to trust them. But I could be wrong! echo
• I'd start by taking it to another dealer. You can buy a whole (used) engine for less than $1300. dlearl #476
• F650 motors have a compression release. Unless it is restrained, a compression test doesn't mean diddly. It should have a leakdown test. If these bozos have been adjusting your valves, you could well have a burnt one thanks to them. I don't know why you would want to pay someone who gets it wrong to learn on your equipment (using your money for their tuition) to fix the error that they made in the first place, also at your expense. Flash 412 (CO)

Recently I braved 20 degrees or so to warm up the oil for another month and test my new polar hands (enclosed handgrip covers for you flatlanders). After about ten minutes of riding time, I apply a moderate amount of right wrist (about 5g's in fourth). There's an audible PFFFT!, my right calf is covered in warm oil and I'm followed momentarily by a large blue cloud which subsides to a small blue cloud. I aim for home watching the oil and temp lights and being very careful. No further problems, other than the persistent small blue cloud following, a little more noise than usual from the valve gear, and a very dirty bike on the right side.

Inspection at home shows that the cam cover gasket is blown out of its recess on the right side, just above the exhaust pipe. I have not touched the valves in about 3,000 miles and nine months, and I believe it was carefully torqued when I did the last check. So what happened? I'm assuming something caused a LOT of pressure to build up in the cam cover. A clogged breather? something frozen (doesn't seem likely or it would have happened earlier)? I still have the carbon cannister in place, a la stock. The bike is always garaged, generally above freezing. bugsy

• This is just a guess and no I haven't checked the FAQ's but it sounds to me that your crankcase breather tube is plugged thus allowing pressure to build inside the valve cover. I don't know how its arranged on the Funduro (the name isn't so bad...there are worse names) But on the CS the breather goes to the airbox. Is it possible that with the 20 degree air condensation inducted into the aorbix froze the breather shut? Just a theory. TOECUTTER (Kreinke)

compiled & edited by Kristian #562
by Gottfried, Team Pami, 29/11/01

Team Pami have had a couple of engines with these problems:

• If you open up your oil filter - which means you should take it apart - you will find the remains of the rod bearing inside. The whole motor is full of "bronze/brass - material bits - look in your oil.
• Another symptom is a feeling of "higher friction" than normal (i.e. bits of metal in your oil), that causes the rear wheel to stop, or "chatter" when you close the throttle.
• Reasons for failure:
  • Not Enough Oil,
  • Wrong Oil Pressure, (Stock Engines have enough, but if you modify them the Oil Pressure will be higher),
  • Poor Oil Quality, Too high an Engine/Oil Temperature (Coolant Leaks),
  • Too much clutch wear.
• The oil light will NOT come on with this failure - the oil pressure is measured "very close" to the pressure pump and the rod bearing "is the last part in the F650 engine" that is fed with oil.
• You also do NOT hear any knocking noise - the engine "dies quiet".
• Team Pami offer an overhauled crank (with a set of main bearings) for 530$ - but need your crank for the core. Don't forget the freight costs and maybe additional tax costs.

Other Symptoms

The bad rod bearings that I have heard keep knocking when the engine revs up. My daughter's bike made more of a knocking noise at higher engine speeds than it did at idle. Richard #230

If the rod bearings are bad then it may be that the water pump may has let the coolant into the engine and diluted the oil. This could explain the oil light flicker at low idle. This happened to my bike 32,000 miles ago but did no damage to the engine. Check your coolant tank and It will be empty. Let us know what you find. If this is the problem probably all you will need is the water pump kit installed and a couple quick oil changes to flush the engine.

See also the FAQ on Counter Balance Shaft Seal Failure.

This is not intended to be comprehensive at this stage as there isn't enough detailed information from older bikes. As the bikes all age and these problems surface, hopefully more details can be added. Hopefully it won't be from my bike. Kristian.

Method 1: Drilling (cylinder head to lower engine bolts)

This method was suggested by Flash for removal of a snapped bolt. The bolt in question is one of those holding the cylinder head to the lower engine. The bolt was rusted, which made if difficult to remove and resulted in it snapping...

• Remove the head, then remove the rest of the bolt. Any qualified machine shop should be able to handle it. Do NOT simply use an EZ-Out.
  
  On a drill press, drill a small hole through the bolt, as deep as the bolt goes. Then drill it again, with a slightly larger drill bit. And again. When you see that you have drilled VERY close to the threads, perhaps even touching them in one spot, get a dental pick and start picking at the remnants. Over-fill the hole with Liquid Wrench or some other potion that claims to free rusted bolts and let it sit over night. With some diligent picking, penetrating oil and time, you will find that the bolt will eventually come out.

Method 2: Using EZ Outs (other bolts)

In most cases you can use this method...

• We mounted the head on a machinist's mill and removed the broken valve cover bolts by using a combination of left handed drill bits and EZ Outs.
• Then we re-tapped all the threads.
• Most of the broken bolts just backed right out.
• I am going to Heli-Coil one of the two cross-threaded holes at my 18K service. It's right out in the open and easy to get to w/o removing the head. The valve cover is not leaking anywhere but the threads in this one hole could be improved.

Once you have gotten the bolts out, you can use a helicoil or a timsert:

• A "new and improved" helicoil. Heli's are pretty much springs that go into the enlarged holes. Timeserts are an entire set of steel threads that are permanently inserted into the hole and glued in place. timserts.
• Here you can see a snapped valve cover bolt.
• Here you can see where a heli-coil has already been inserted (and a snapped/sheared bolt too!) - valve cover bolt.
• And this is a bolt from the Cam-Chain plastic T-bone (Be sure to contact Sadlsor and thank him for demonstrating this clever trick).

Can I ride my bike without a valve cover bolt?

• Get the bolt before you ride it. It will leak oil all over the place, make a mess and you will definitely ruin your engine paint trying to clean the cooked(coked) oil off of the engine. Plus you could leak oil on the rear tire, skid, crash, lowside, kill yourself, then no jesse on f650.com. jetdocs550
• You can't ride without it. Well... I guess you could if you seal the hole in the valve cover. Worst that will happen is the cover will leak. Flash 412 (CO)

I came across a reference to Duane Ausherman's site on BMWMOA.org/Forum. Duane was an old hand with BMWs when I came on the scene. I have a LOT of respect for the man and his experience. There is a LOT of great stuff on his site. Then I read this... this...

Ring gaps for the BMW motorcycle

The Myth
Everybody "knows" that ring gaps must be placed away from each other. The fear is that the compressed gases would leak out if the gaps are lined up. Many suggest placing them at 120 degrees from each other to reduce leakage. If you are using the BMW ring compressor, that makes it a bit slower to reach around and under the piston to shove those ring ends into the cylinder. Let's think about this for a moment.

The Reality
Each time the crank makes one revolution the piston also travels up and down one time. For easy math let's use 6000 rpm. During one second the piston makes 100 trips up and down. True, only 50 are compression strokes, but for this discussion of time it matters none. Half of the trip is downwards and there is no compression. The half going up is now happening in 1/200th of a second. That isn't very much time. If all of the ring gaps line up, how much compression do you think is lost by gas going straight through them? Nothing worth considering.
Now lets think about another issue. The rings don't stay in one place. Proof is twofold.
1. A two stroke engine has pins to locate the rings to prevent them from rotating and getting caught on the open ports.
2. Set your ring gaps anyplace you want. Ride the bike 1000 miles and remove the cylinder. You won't find them in the same place.
This means that you must accept rotating rings, redesign the pistons to locate the rings or remove the cylinders very often to put them back where you have decided that they belong. I think that the first one is the best one. Forget about the ring gaps.

Anyone want to discuss it? Flash 412 (CO)

• Ask Chris Ratay about ring gap. He bought a " matching " piston, rings and cylinder from bmw and the ring gap was several times the allowed gap. He used oil at a alarming rate in places where decent oil was hard to find. He finally took the engine apart again and fixed the problem. I don't remember all the details but that was the most of it. Steve#417(in,us)

• I always have, and always will, space the ring gaps on a two ring piston at 180 degrees separation and 120 degrees on a three ring piston. I really don't know if there is enough time for the squish effect to reduce copmpression thru the gaps or not. However, compression is one of the requirements for cranking/starting an engine and it seems to me that a straight line down thru the gaps would mean a real drop in compression pressure. All ring/piston combinations that I know of have a gap measurement specification which further makes me think that there must be some reason to not have too large a gap; i.e. a loss by the first (top/compression) ring and the same thing for the next and the oil ring.

  I agree on using fingernails on the boxer engine and a ring compressor, properly clean and oiled, on a normal auto block engine. I have built a number of engines using the old pre-WWII Crosley engines which had the block and head made in one piece. After putting the valves in, the piston/rod assembly was installed, then the crankshaft installed with half of the main bearing shells, then the base and the main bearing caps, then the oil pan......of course, with the oil pump, etc. That was timed with a tower shaft to the single overhead cam. That engine displaced 750cc and we routinely turned them to 9500 rpms before shifting and to 11500 if needed....and that was many years before synthetic oils, CNC machining, electronic ignitions and really modern metallurgy. Ike647

• What about Total Seal Gapless Rings? R4ND0M_AX3 BBG#45

Has anyone ported or polished their own intake on a classic or a fuelie? damalden #1598

• Why bother? If you DO polish it, be sure to have it bead blasted afterwards. A rough surface makes MORE power than a smooth bore. Flash 412 (CO)
• DON'T make your ports any bigger. It slows velocity and robs power unless you are doing a whole bunch of other stuff as well. Just smooth off any bumps or flashing left from the manufacturing process. You can polish the exhaust ports if you like, but it's mostly a "feel good" thing. DON'T polish the intake ports. The rough surface causes the air to "tumble" somewhat, leading to better fuel atomization. blewbyyou

I am putting a pre-97 motor in my 99' classic. It has the old countershaft sprocket circlip/crappy way of mounting the sprocket. Has anyone every switched that out with a currrent one? Can everything switch between a pre-97 and a 99' model? XtreemLEE #1188

• You have two choices. One is to just paste in the new motor as-is. The other is to split the cases and swap the countershaft. It is probably easier and better to just swap whole transmissions. While you're in there, you should probably get an updated second gear shift fork for about $45.

  In any case, be SURE to get the second DVD that Artyom and I made before you do the swap (and maybe split the cases). There are some tips and tricks in there for dropping and reinstalling the motor and splitting the cases.

  If I were in your position, I would probably split the cases on the "new" motor and stick the second gear fork in it while it was out and LOOK at what's inside. I would probably leave the circlip type countershaft in it, but use the RIGHT kind of circlip (external) or snap-ring. Slop some silicon sealant on top of the retainer and carry a spare. You'll probably never have a problem. Flash 412 (CO)

Does anyone know, or have experience with a swap of a newer F 650 GS engine into an older ST frame? Will it fit in as a simple bolt in with the same mounting configuration? Specifically, I am interested in fitting a 2001 gs engine into my 1999 ST. ddishman

• Based on the GS engine I've seen on eBay with NOfit in the ST frame, the engine mount points will be different. (DISCLAIMER: I've never attempted to, much less successfully transplanted any variety of BMW 650 motor) Sadlsor #1444
• Even if you could, why on earth would you want to? Not only is the pre-GS motor mo' better, even if you got the GS motor for free, it would be cheaper to buy a new bike than to replace all the bits you'd need to replace to run the FI. dlearl #476

Can someone tell me what part this is and what it does? And how come there is not one on the other side? Educate me. billmallin #1629

• I'd have to say that is the automatic compression release. I believe it holds one of the exhaust valves open during startup, to make it easier for the electric starter to turn over the engine. It flips out of the way once the bike starts. shafted
• Compression release. Spring loaded to open one exhaust valve while the piston is on it's way up during the compression stroke. The valve is fully closed at TDC so there will be no leakage should ignition occur during the start cycle. Increased engine RPM (ie engine catching and running) and the accompanying centrifugal force pulls the flyweight to oppose the spring force and rotate the compression release to the retracted position. jetdocs550 #1546

This currently only appears to be a problem on the GS's. APPARENTLY, (and AFAIK this has never been confirmed) BMW or their subbies, put the paint on TOO thick OR the 2nd layer on TOO SOON and it never dried properly, remaining soft, which when heated by the engine, simply allowed gas expansion to form the bubbles. Kristian#562

Minor Instances

Minor cases can usually be identified around the small plastic plug on the RHS of the engine case. You can also find evidence around the coolant hoses on the LHS of the engine case. [Look closely and you will see small "bubbles" in the pictures].

• My '04 GS does that around the plastic cap, but it is not happening around the water pump. 26k kms on the clock. I just assumed the brains of the bike were leaking out somewhere. Winter #1935
• now that i look at it, i have a little there too. i just turned 20k yesterday rob feature
• Mine's doing it there and also where the coolant hose meets the engine. I just popped it off (very carefully). If I get a chance later today, I will snap you a couple of pictures... Namebrand #1629

Major Instances (Chicken Pox?)

These are some major cases of paint bubbling:

• Kristian#562 (2001 GS @ 22k kms) - see next bullet by Kristian for pictures taken later:
  • RHS (bad)
  • Engine (minor)
  • LHS-numbers (minor)
• Kristian#562 (2001 GS @ 40k kms): Note that I basically popped all the bubbles. It doesn't look quite so poxy that way... but still ... This is the situation on my '01 GS @ (now) just 40k Km's - I do lots of in-town riding. LOL, of course I do, I live in a BIG CITY. There IS no real country...
  • RHS (really bad)
  • LHS (fine)
  • LHS (close-up, minor)
• Daniel's Similar Issue:
  • LHS numbers 1
  • LHS numbers 2
  • LHS water pump
  • RHS near spark plugs 1
  • RHS near spark plugs 2
  • RHS near exhaust
• Haakon's in Norway (More of Salt thing I think):
  • LHS water pump
  • LHS engine
  • LHS above water pump
• reichew (Singapore) - Hi, I've been riding my 650GS for about 6months now-(bought 2nd hand with 4700KM on the dial). I've observed that the paint around the cylinder body and the water pump casing is blistering. It seems to get worst at the days goes... I've checked with the dealer in Singapore- he replied that this is normal as the paint will blister and that there is nothing wrong mechanically- I've used a infar red temperature gun to measure the cylinder body and all associated parts temperature- the highest was ...
• BG - That's pretty nasty all right. I have a small bubble on mine I spotted a while back but so far it has not gotten any worse and is no where near as bad as yours. Mfg date for mine is 01/01 (or is it 05/01)
• Andre - My 2001 F650GS has bubbles like poxy 3 but worse. It is out of warranty now so never even asked if BMW could fix it:(
• Oyvind - Don't have a digital camera yet, so no pics. But the paint on the fwd part of my engine is pretty much flaked off now in many places. Also a problem on sharp edges. I've attributed it to winter riding and road salt previously, so I've never filed a warranty claim for it, and it's too late now. OTOH, why did they paint it in the first place? Aluminum is notoriously difficult to paint properly, anyways, due to poor adhesion to the alu oxide. They could have just anodized the aluminum and left it at that, like most other mc engines out there. Oh well, can't see it when I'm riding, so who cares
• red_alert (ALSO Singapore) Almost all of the 650 GS that I know has this problem, some bad, some really bad.... mine is starting, hope it wont get really bad..... my friends too say its the climate that cause it.... sigh.. guess BMW never thought of us in asia when they paint it. F650GS, Singapore.
• dhp75us from NY on a Classic has this picture
• I have a '99 Classique (72K miles) with the bubbly paint, 'twas there from the moment I purchased at one year old and 11K miles. I don't really care about it, it's an aluminium engine so rust is not a problem. Shank in Colorado #974

Solution

Frankly, I can't see a remedy as such, except for "remove, strip off teh paint and repaint" I was thinking about a new cover frankly, but (a) It's expensive and (b) what guarantee do I have that it won't happen again....none. It's annoying, and it certainly doesn't help when you go to sell it (so keep it!) but I do think it's largely cosmetic. Kristian#562

Does anyone know if the motor ('01 GS) is interfering or non-interfering (ie - does the piston hit the valves if the timing is way off). I had the cams out and put them back with respect to what I thought was the hole that you thread a bolt into to lock the engine. maybe it was the wrong position hole on the flywheel. It doesnt really sound or feel like the engine has compression anymore. Is the hole supposed to lock the engine at true TDC? I can find tdc but I am not exactly sure what position the cams should be at this point and there was no hole at this position when I started. petes101

• Yes. It is an interference motor. Flash 412 (CO)
• There are no "holes in the flywheel." The TDC bolt goes into a slot in the bobweight. Remove the valve cover. Put the motor on the compression stroke and install the crank stop bolt IN the slot. Then measure your valve clearances. If they're off by a LOT (>0.020") then you have bent your valves. But, if the motor was running and just felt weak, odds are that you simply missed timing by a tooth or two on one or both cams. Flash 412 (CO)
• There is only ONE hole for the TDC bolt to lock into the flywheel, and only one place to put that bolt. That IS TDC, and there is just one place where it's at TDC as the cams rotate. Sadlsor #1444
• Right - but you see the slot twice in a full cycle of the engine (2 rotations). You need to make sure that the cam lobes are pointed the right direction when you see the slot, and that is TDC. dinskeep
• The piston is TDC on compression and on overlap. The ignition is a wasted spark design. So, it really doesn't matter where the cams are when you stick in the TDC bolt. But you make less work for yourself if you stick it in when the valves are at compression because then you don't have to take the cams out and flip them over before measuring the valve clearances. Flash 412 (CO)

• The engine number on my 1993 F650 is punched transversely (crosswise) clearly into the crankcase on the upper side of the case above the large transverse stress-bearing bolt. (There are black plastic grommets where your ankle sits when riding which cover the ends of this bolt.) Engine number is visible when looking from the bikes rear wheel past the mono-shock with bike on centre stand. My number is in the format 123456789VA (9 numbers + 2 alphas.
  
  "Rotax", "Made in Austria" and a small circle with 93 inside (the YoM of my engine) are visible on the sides of the left side of crankcase down under front of gear lever area - plus a raised number in the casting -- which is NOT the engine number.
  
  Anyone know how to de-cypher my engine number for information? Charlie (by email)

• I just found this very cool animation of Desmodromic valve actuation. No, it has nothing to do with the F650. But somewhere I have photos of a BMW for which someone created a Desmo top end, which gets me to thinkin... Flash 412 (CO)
• behold the non springiness! no valve float at high rpms, probably other advantages too, not that you need a 650 thumper spinning at 18,000 rpm colin
• its a ducati term, so presumably italian, a velo drome is a closed loop track for bicycles so it probably a passing reference to the cam profile, but then i could be out to lunch. colin
• The word "desmodromic" is derived from two Greek roots, desmos (controlled, linked) and dromos (course, track). It refers to the exclusive valve control system used in Ducati engines: both valve movements (opening and closing) are "operated". JR_Dakar

ok so on my newly aquired f650 my friend had me listen to it with my helmet off and wow, was loud coming from header or exhaust up front. only had it 4 days pulled the exhaust and no gasket in connector? just sitting in there! omg did i buy a basket case?????? so i pull both header pipes and start removing the ring gaskets left one came out easy other wouldnt budge.. so after 30 min trying to get this thing out i start hammering my screwdriver under the gasket, ouch i gouged the surface pretty good what do i do.... saswok

• Nah, you can probably take the head to a machinest and have him repair it. Flash #412
• Hammer + screwdriver = bad djw #1736
• Not sure what you gouged, but can ya get a Dremel tool in there to grind the lifted metal down? Can you then CAREFULLY apply JB Weld to the valley of the gouge? Jam some cloth behind the area so particles do not enter your combustion chamber. I am assuming you have only gouged the exhaust port, no? If so, all ya gotta worry about is effectively sealing the exhaust system. Mista Vern

• DVD #3 will cover removing the valves. Valve guides cannot ever be removed and reinstalled. The hole in them is intentionally undersized when they're manufactured and they get reamed after installation. This ensures the hole is straight and true and the right size. Then, the seat gets cut (or lightly dressed). Flash #412
• Removing valve guides is easy. You break them off at the clip and then drift the stub down through the head. Flash #412

Most of the performance improvements for the Rotax 654 engine are for Classic (Carb) models. The reason for this is changes to the engine on Fuel Injected models will likely cause problems with the Fuel Injection system. And since BMW does not let us know how to change / adjust the FI system, there is not much choice.

Ron Woods Kit (Classic Only)

• http://www.rotax.net/
• Multi-stage performance kits:
  1. Bolt on kit: 68% boost in torque at 3700 rpm and 32% more horsepower at 7700 rpm, plus the rev limiter is eliminated giving another 1000 rpm to the rev range.
  2. Kit Includes stage 1 parts, plus the following parts for additional performance: High compression forged piston, Performance racing cams, Dual racing valve springs with titanium retainers.
  3. Includes all of the parts from stages one and two, plus extensive modification to customers cylinder head
• See the Ron Woods site for more detailed information.

MSD Cams

• http://www.msd.it/ (Translated page of MSD)
• http://www.msd.it/
• http://www.motok.gr/manuf.asp?nm=MSD&startat=5 (listed for F650 GS and CS)
• There are whole books on cam design, lobe centres and timing . And they dont always agree on what is best. But it seems that dailing in the cams so that the opening and closing points and lobe centres are exactly where the manufacturer intended them to be on all valves will give good power gains on most engines. However as this can involve stoning the cams you would want to know what you are doing. And a selection of offset keys or adjustable camchain sprockets are essential too. I dont know what the lobe centres currently are but there are a few people who should know who reccommend 102/105 degrees as a good figure for high rev peak power, and as much as 10 degrees more for a broad spread of low rev torque beemerboff
• It just does not add up to me (but then again, I know very little about Cam timings etc). I just figure a conventional cam timing would have been optimised for performance and longevity. Offsetting the cam lobes from each other to gain HP, says to me something else must be lost elsewhere. How does it affect fuel consumption and lifespan of the engine? Winter #1935

Web Cam Racing Cams (for the DS650)

• This company seems to make high performance cams for the Bombardier DS650 - which is based on the same engine as the F650s (the Rotax 654 engine).
• See http://www.webcamshafts.com/pages/bombardier-atv.html
• It is unknown if these cams would work on a F650 (Classic or GS/Dakar). If you want to try, please let us know how you go. The company may do some custom work if you are willing to pay.
• Web Cam Inc.
  1815 Massachusetts Avenue
  Riverside, CA 92507-2616 USA
  webcamshafts.com
  
  Phone: 951.369.5144
  Fax: 951.369.7266
  Monday - FridayM
  8:00AM - 4:30PM

BoonDockers NO₂ (Nitros Kits!)

• Again, no one has installed anything like this on a F650 (Classic or Fuel Injected that we know of). If you do install a kit - please let us know so we can tell others about anything you did.
• See http://www.boondockers.com/
• For specific instructions see: http://www.boondockers.com/support/downloads/documents/ATVs/Bombardier%20DS-650%20ATV.pdf

• Note: The alternator of the F650 GS/Dakar/CS is 400W. There is no known alternator larger than this. A previous misconception was the GS/Dakar/CS models with ABS had a 580W output. This was incorrect.
• Electrex (electrosport.com) has an upgraded stator for the classic: http://www.electrosport.com/shopping_stators/prod_esg070.html. They don't list how much extra it gives over the standard 280W for the classic, but I asked them via email last fall and IIRC it was something like 320 or 350. Nothing huge, but enough to add lights if you're already maxed out.