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
Also see the following FAQs:
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).
Strange Engine Noises?
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
- "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
- 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.
- 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.
Complete New Engine?
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:
How much does the engine weigh?
- 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)
Catastrophic engine failure
|Rotax 654 failures are rare!|
|The Rotax 654 engine is generally considered bomb-proof. Many people
will put more than 200,000 miles (320,000kms) on an engine before it needs any serious maintenance. As such, major engine failures (such as shown below) are very rare for the Rotax 654. Don't panic reading this story - your engine will not explode unless you do something really really stupid. However if your engine does explode, please let us know why, and take some pictures!|
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
- 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 :^( ?
- 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
- 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.
- 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
Catastrophic engine failure - Part 2
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
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
Turns out the piston has been reduced to little chunks of metal. See it
I fished out this little piece and put it on the haed to give you an idea
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?
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
My '99F with 19k miles has been running progressively worse for several
months now (details below). I recently took it in to the San Francisco
dealer for a Level II service (at 18k) and hoped that that would fix the
problem. Instead, its been in and out of the shop 3 times in the past
month, yet the problem has only gotten worse. Today the dealer said that
he found "65% leakage" in the leak down test and therefore I need a head
rebuild for $1300. Ouch!
I'm no mechanic so I can't really say, but they've gotten the diagnosis
wrong twice already. In their defense, they have been very apologetic and
will refund what I've paid to date but I'm not sure I want to pay for a
$1000 guess. I'd appreciate any suggestions or cheaper alternatives.
Here's the history:
I bought the bike used 3 years ago with 10k miles. I use it primarily
for city riding with the occasional (once a month) long highway ride. It
ran great for about a year but since then has gradually gotten worse in
performance and gas mileage.
In the last several months it has gotten significantly worse,
especially when the weather is cold or wet. Its taking increasingly longer
to warm up and I can't just let it idle to get warm. The engine seems to
have to be working in order to overcome the problem. Right now it takes
about 10 minutes or more and until its warm it will not go above 3500 rpm
(while moving). As soon as it hits 3500, it stalls, stumbles, surges,
bogs down, and sounds very rough, until I pull in the clutch or upshift.
I've almost dumped it several times when it bogged down in a turn. After
its warm it seems to run ok. lessikos
- 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)
Blown Cam Cover Gasket?
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
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)
Rod Bearings Failure
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
- 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
- You also do NOT hear any knocking noise - the engine "dies
- 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.
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.
|Removing snapped / sheared bolts is not easy|
|While this section may help someone unfamiliar with removing snapped or sheared bolts, it is highly recommended someone experienced perform this sort of work. You can end up with a very expensive mess if you get it wrong. However if you are in the position where you must do it yourself practice first on something other than your bike. Even if you have to spend $20 at the local junk yard, it is far better to waste that $20 than pay $500 for a replacement part.
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
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
- 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
- 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.
- 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...
Ring gaps for the BMW motorcycle
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.
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.
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
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.
- What about Total
Seal Gapless Rings? R4ND0M_AX3 BBG#45
Ported and Polished Intakes
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
- 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
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)
Will a GS engine fit in an ST frame?
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
Compression Release Mechanism
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.
- 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
The paint on my engine is bubbling?
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 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:
- 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
- Daniel's Similar Issue:
- Haakon's in Norway (More of Salt thing I think):
- 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.
- dhp75us from NY on a Classic has
- 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
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.
Is the Rotax engine (used in the F650) interfering or
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)
Where do I find the engine number?
- 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
What is Desmodromic valve actuation?
- I just found this
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
- 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
Gouge in cylinder-head?
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)
- Multi-stage performance kits:
- 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.
- 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.
- 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.
- http://www.msd.it/ (Translated page of MSD)
- 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
Monday - FridayM
8:00AM - 4:30PM
BoonDockers NO2 (Nitros Kits!)
Increased Alternator Output
- 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.