Flywheel questions and oil leakage

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UpsMan · #1 Post by **UpsMan** » Mon Jun 29, 2009 2:21 am

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I have a couple of things going on here. A fair amount of oil is leaking from the seal behind the stator. The oil in the picture is from a half hour of mx riding. The other thing in the pictures, is the used flywheel I'm using until my new one comes. I marked it so I would know if it spun. Well, I took the cover off to see how much oil was leaking, and it looked like it had spun a tiny bit. Odd thing, I can move the outer hub on the inner hub about a sixteenth of an inch maybe. It is still running good. I cant believe the two pieces are so loose. In one of the pictures you can see oil that has come out of the flywheel from moving it back and forth. Has anyone ever seen this? I can't believe this doesn't just fly apart.
Any comments or info is appreciated. Canniboomer, I think I need the replacement seal you have.

haydug · #2 Post by **haydug** » Mon Jun 29, 2009 3:56 am

I had a seal leaking pretty bad one time, it actually stalled me in the first moto, basically the crank pickup wouldn't read because of the oil, so I cut a hole in the bottom of the cover, and rode it the next moto and finished. Funny the stuff you will do to finish a race.
As for the flywheel, I've seen them look cracked around the center and full of oil, but still run.

TricityCdale · #3 Post by **TricityCdale** » Mon Jun 29, 2009 3:16 pm

I have the EXACT same thing going on. I believe my situation is being caused by the check ball in the oil pump not sealing and oil is slowly filling up the crankcase above the level of the crank seal. I get over 1 qt of oil out of the crankcase when I pull the drain plug. It is a real PITA because it doesn't charge the battery very well and will cause the quad to stall at inopportune times. I'm going to check with Boomer to see what can be done about it.

I have Boomer's oil seal too, but I know I need to address the root cause, because it still leaks.

kdeal · #4 Post by **kdeal** » Mon Jun 29, 2009 3:22 pm

Roger,

Do you mind if I ask where you got your crank from? It's not to place any blame, I'm looking for a common denominator here. There has to be reason for all of the spun flywheels. The oil leak may be related. PM me if you don't want the info public.

Ken

TricityCdale · #5 Post by **TricityCdale** » Mon Jun 29, 2009 4:27 pm

QUOTE (kdeal @ Jun 29 2009, 08:22 AM) <{POST_SNAPBACK}>

Roger,

Do you mind if I ask where you got your crank from? It's not to place any blame, I'm looking for a common denominator here. There has to be reason for all of the spun flywheels. The oil leak may be related. PM me if you don't want the info public.

Ken

Just to clarify, I DON'T have a spun flywheel on mine, just the oil leak. Sorry for the confusion.

jesshamner · #6 Post by **jesshamner** » Mon Jun 29, 2009 4:51 pm

QUOTE (kdeal @ Jun 29 2009, 11:22 AM) <{POST_SNAPBACK}>

Roger,

Do you mind if I ask where you got your crank from? It's not to place any blame, I'm looking for a common denominator here. There has to be reason for all of the spun flywheels. The oil leak may be related. PM me if you don't want the info public.

Ken

I thought about that too when I posted on someone elses oil leak problem. I had a leaky seal and eventually spun the flywheel. After replacing the seal and getting a new flywheel all has been good. The only problem with my scenario is that the time between events is too much. My seal leaked for the first year I had it. Then I fixed it. The flywheel didn't spin until the 3rd year.

cannondale27 · #7 Post by **cannondale27** » Mon Jun 29, 2009 5:16 pm

This oil leak has been going on through two different cranks.First one had 3 years on it.This is a whole different new crank.When removed the old seal was in crooked because of the use of wrong spacer behind the stator pressure pushed it out.This is a new Canniboomer seal in there with correct spacer.Not sure what is going on.Pressure tested and looked for cracks and I couldnt find any.

TricityCdale · #8 Post by **TricityCdale** » Mon Jun 29, 2009 5:25 pm

QUOTE (cannondale27 @ Jun 29 2009, 10:16 AM) <{POST_SNAPBACK}>

This oil leak has been going on through two different cranks.First one had 3 years on it.This is a whole different new crank.When removed the old seal was in crooked because of the use of wrong spacer behind the stator pressure pushed it out.This is a new Canniboomer seal in there with correct spacer.Not sure what is going on.Pressure tested and looked for cracks and I couldnt find any.

I just spoke at length with Boomer about my crankcase volume/oil seal leakage issue. Hopefully he'll chime in with his thoughts. Basically, he said that it's possible to leak unfiltered oil into the crankcase from the balance shaft. If the clearance gets too much, it can seep in that way, even if you have a good checkball in the filter assembly.

I'm going to test mine tonight by running it for a while and then immediately draining my engine sump and measuring how much oil I get out of it, to see if I've got an issue with the scavenge pump.

My motor has about 8 hrs on it right now. It didn't start leaking through the seal until it had about 6 hrs on it. I've replaced the seal with the new Boomer seal, but it still leaks.

peterock · #9 Post by **peterock** » Mon Jun 29, 2009 8:32 pm

You could check to see if it is leaking after running or after it sits. Clean the cover out and leave it sit for 24 hours. Take the cover back off and see if there isn't any oil. If there isn't, then maybe it's an issue of the crank bearing going out? Little bit of play.......and I mean just a slight/little bit of play may allow some oil to weep past the seal while it is running?

Just thinking out loud.......

rayspeed · #10 Post by **rayspeed** » Mon Jun 29, 2009 10:00 pm

I wonder if a check valve could be incorporated into the oil inlet adapter fitting that would eliminate this drain back problem.
Seems like a little little press in seat, some machine work and a spring and ball with a groove for a snap ring would do the trick...
Just thinking out loud, I have one that has the leak back problem but no problems with that seal yet...
All of these semi dry starts with all the oil in the motor and not in the frame has to be shortning the life of our motors.
Ray