LT500 87 I pulled the flywheel to ck my timing mark 2 weeks ago and all was dry! I've started and let it run for awhile since. Just pulled the flywheel again to install new 130w light stator and oil poured out of L. case side. Pulled the stator and saw the oil seal all the way out. Put it back in and fit real tight not loose at all. Good thing I went in again before a ride! Anyone have any thoughts or experiences with what caused this? I've ordered another seal yet worried about this possibly happening again with maybe an internal combustion situation of some kind. Hope its nothing serious! Is there a way to hold the new seal in besides just the seal holding itself in place? Thanks
How much oil came out of the stator cover when you opened it up?
seal need to be glued in place with thread lock
(as instructed in the factory service manual)
Any idea why it popped out? Thanks for quick reply!
it poped out because you never read the service manual :-)
I'm sorry I didn"t explain thoroughly enough. I never installed the seal it came out in between the two inspections and I had only ran it for just a few minutes between those times I ck. it. I never messed w/ the seal. I just bought the quad a few months ago. And there were no backfires while starting. I'm lucky I went back in to install the stator or I would have possibly froze up the engine! Any idea what caused the seal to blow out.
The most common cause of crank seals coming out of the case is trying to start the engine when the crank case has fuel in it. If the petcock is left on or the petcock does not shut the fuel off 100% to the carb and the carb float valve is not in tip top shape, the crankcase will fill up with fuel in a short time.
Using thread lock will help keep the seals in place under normal operation but will not hold the seals in place when the bottom end has experienced a hydraulic liquid lock or a severe crankcase backfire.
Some engines have a plate or a set of tabs that prevent the seals from pushing out of the crankcase. When these engines experience a hydraulic liquid lock in the crankcase, the reed petals or the reed cage dividers will often break spewing reed cage fragments through the engine.
Consider yourself lucky that the seal pushed out of the case rather than destroy the reed valve. When the ignition cover has a good gasket and the stator wire grommet is in good shape. the air leak is minimal. The engine will usually run fine without experiencing a lean condition but may suffer a small power loss due to the increase in crankcase volume.
Any idea what caused the seal to blow out.
Well most likely the crank has some play in it, the seal could have not been properly, or like Jerry said it was hydraulic, and the compression forces from the cylinder blew it out. Since it was not a lot of oil it was just 2 stroke oil build up.
I would either get a new seal and put it in or use a little thread locker and put the old one back in, if it's in good condition. Problem with using the thread locker and the old seal is that it may blow out again if the seal integrity has been compromised. I would also use a little white lithium grease on the inner sealing lip when installing it.
Even more importantly than that, is once the crank seal is compromised (or blown out) you now have a air leak and if your stator cover is not sealed good and your stator harness plug is not good then your drawing in air that does not have fuel and OIL in it. This will cause a lean condition and likely lead to piston seizure or failure depending on how hard your pushing it, possibly breaking other things as well at the time of failure.
Get a good crank seal in there and see how it runs and check to make sure it does not blow out again.
Then you can jet the bike properly once your engine is sealed up.
Wow that's a lot of great information! In regards to crank movement. I did pull up and down back and forth real hard with no movement. Would using a short shot of starting fluid cause the seal pop? Had a hard starting condition w/ our 20 deg. mich. temp. and fired right up! I also shot it in w/ carb slide closed. Did I possibly cause the seal to pop doing that?