No compression

[nedburt]

Just got back from Alaska a few days ago. Did some maintenance; chain and sprockets, brakes, tires, nothing with the motor or electronics. Went out to go to work this morning, it cranked normally for half second then started cranking fast like there is no compression. Any one else experienced this?
Never had a problem out of this bike for 50,000 miles, thank God it didnt do this in Alaska.
Thanks, Chad

 

[nedburt]

Almost forgot, when I tried to start the bike, it reset the clock and trips.

 

[Shamus McFeeley]

Did it make any kind of noise while this happened? Did the bike try to start, or just crank? If the gauges reset than you might want to check your battery terminals. Even a total loss of compression on one cylinder should not make the engine spin that much faster. Unless all of your spark plugs backed out at the same time, I don't think a compression loss is your problem.

 

[nedburt]

There was no odd noise like anything broke, just went from cranking normally to cranking "faster"(for lack of a better word). Checked all fuses. Checked for spark on one cylinder, ok. Something definitly happened when I cranked it over; the bike hasn't been ridden or ran since I got back from my trip. I'm thinking something electrical, which terrifies me. I got the diagnostic display up on the dash, but other than the first one being for the TPS, don't know what the other 50 mean. The fuel injection still kicks on when you turn the key.

 

[jazzpaintball]

There was no odd noise like anything broke, just went from cranking normally to cranking "faster"(for lack of a better word). Checked all fuses. Checked for spark on one cylinder, ok. Something definitly happened when I cranked it over; the bike hasn't been ridden or ran since I got back from my trip. I'm thinking something electrical, which terrifies me. I got the diagnostic display up on the dash, but other than the first one being for the TPS, don't know what the other 50 mean. The fuel injection still kicks on when you turn the key.

First off, what is idle speed. You are gonna want to check that with the tach. If it is above 1350 (when engine is at operating temp) then you are gonna want to turn it back. Having the idle set screw turned up will definitely make it seem that the bike is cranking faster.

 

[Capo79]

Are you sure it actually cranked when you say "cranked faster"? I know from my own experience when the battery went flat, that the motor cranked for half a second and then just a fast loud ticking sound (in lack of a better word). The clock and trips got reset for me also...

What you can do of course, is to hold you hand behind the exhaust and feel whether or not there are any gases coming out when this happenes. If there are, well then you're right. Something is definately wrong. If nothing comes out of the exhaust, then I'd recommend swapping out the battery or charge the one you have:thumbup:

 

[RJ2112]

Almost forgot, when I tried to start the bike, it reset the clock and trips.

First suspect is the battery. Is it the OEM unit?

 

[seb101]

im pretty sure it's dead battery, try to bump start it from 2nd gear and go for a ride for couple of km's. If you're using headlight mod and other electronic accessories the battery isn't almost charged when it's on idle speads so you have to keep it running (in manual it says above 5000rpm but someone on the forums found that if it's above 2200rpms it's doing the same)

 

[nedburt]

Thanks for the responses guys. Def. not the battery. The motors turning over just doesn't sound the way it should. Almost feels like its sucking air into the exhaust when you crank it. My Dad thinks its not getting any gas, therefore not compressing like it should.
Does anyone know where I can find out what all the diagnostic codes mean? I'm going out of town for the weekend, be back Sunday to mess around with it some more. Thanks for the help!

 

[TownsendsFJR1300]

Page 8-35 for an 07 shop manual, #50 is an ECU malfunction:

"ECU internal malfunction
(memory check error)
Faulty ECU memory. (When this
malfunction is detected in the ECU,
the fault code number might not
appear on the meter.)
Unableto start, Unable to drive

 

[skooter65]

I would have to agree that the battery would be my first suspicion. When you crank the bike over, two things happen: First, Then Bendix Drive of the starter (Which is actuated by a rather large, energy sucking solenoid) engages the output gear of the starter to the corresponding gear on the engine; Second, The starter motor begins rotating to begin cranking the engine. More often than not, a dead/dying battery will not have enough power to actuate the Bendix drive, usually resulting in a "clicking" sound. Less frequently, there is just enough power to engage the Bendix and rotate the starter motor but, as soon as the starter motor spools, it has drawn too much power from the dying battery and the solenoid trips off and the starter spins freely disengaged from the engine (Long winded sentence, My bad). The free spinning starter spins much faster and louder than an engaged starter (Perhaps confused as loss of compression, faster spinning engine).

I may be wrong but my 0.02$

 

[champion221elite]

Thanks for the responses guys. Def. not the battery. The motors turning over just doesn't sound the way it should. Almost feels like its sucking air into the exhaust when you crank it. My Dad thinks its not getting any gas, therefore not compressing like it should.
Does anyone know where I can find out what all the diagnostic codes mean? I'm going out of town for the weekend, be back Sunday to mess around with it some more. Thanks for the help!

Even in the absence of fuel, your motor should still have compression if it's healthy. Compression is a product of the cylinders ability to completely seal a volume of air within the combustion chamber. During a cycle, air is ingested through your intake valves and compressed as the piston travels upwards. The exhaust valves are closed and the air charge is compressed several times greater than atmospheric pressure. If your engine truly lost all compression at once, I would be looking at your timing chain, sprockets and cams. A faulty valve train may prevent the proper intake of air, or the inability to hold the air charge in the combustion chamber. Piston rings also play a role in holding compression, but all 4 pistons won't fail at the same time. I would take a look at your valvetrain just to make certain it's good to go.

 

[Motogiro]

Just got back from Alaska a few days ago. Did some maintenance; chain and sprockets, brakes, tires, nothing with the motor or electronics. Went out to go to work this morning, it cranked normally for half second then started cranking fast like there is no compression. Any one else experienced this?
Never had a problem out of this bike for 50,000 miles, thank God it didnt do this in Alaska.
Thanks, Chad

From what you've explained it almost sounds like the drive gear on the starter motor let loose. I know you said you got an error code. Can you bump start the bike?
Timing chain might have let loose and left some valves open hence low compression? Check to make sure timing chain is engaged....If it did and you cranked it you could have bent valve stems with valves open...

 

[aussiejules]

as has been said no fuel will not make you loose comp, loss of comp will only happen from valves stuck open, when you tried starting it the first time was there any hesitation before the sudden faster cranking? pull the plugs and crank it you should get big gusts of air rushing out of the cylinders

 

[oldfast007]

I may be way off base in this one...(forgive me if I am) but couldn't you put it on the center stand click it up to 4-5-6 gear (if you can) and with the help of a friend see if you can spin the real wheel to see if the engine turns or has good resistance to the force applied?
If it spins rather easy, would you be able to hear something in the valve train or other related component to further asses the issue??

Of course as a mechanic I make good plumber...:tard:

 

[champion221elite]

Any updates from the OP? I'm curious to see how this situation ends up.

 

[TownsendsFJR1300]

A "You Tube" of the bike being cranked over would make it considerably easier to determine if its the starter gear spinning up (without the engine) or the engine spinning freely(or not).

Pulling a valve cover or timing chain cover would also be a good tell tale as to what's going on (or not).

 

[nedburt]

Still here guys, I'm out of town this weekend and haven't had a chance to tear into the bike yet. I didn't get an error code. When I get home I'll take a look at the timing chain. There was no hesitation before the faster cranking, it cranked normally for about half a second. There wasn't any noise like anything breaking. I'll keep you all posted, thanks again for the interest.

 

[deeptekkie]

I'm glad this didn't happen on your trip! I have a headache and I have not read all of the replies but if it won't actually start - just cranks over fast, did your cam chain break maybe, (keeping some of the valves partially open)? Just a thought. Good luck.

 

[nedburt]

just pulled the timing chain cover and rotated the back wheel in gear, all is good there. I guess next step is to pull the valve cover? The compression felt about right when I spun the wheel in 6th, think it would hurt anything to try and bump start it?