Oil leak behind sprocket
- KDXohio
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Oil leak behind sprocket
Changed from the stock sprocket to a smaller one and immediately developed an oil leak from the output shaft seal replaced the seal and all is well also put the stock sprocket back on 14t I believe. Anyone else ran into this problem?
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
- rbates9
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Oil leak behind sprocket
The area is sealed up by,
The seal
The collar
Two o rings, on the H anyway
The sprocket
The snap ring
The reason for the two o rings is to preload the collar. So, if the new sprocket you put on is thinner even by just a little the collar will not have the preload on the o rings and let the oil seep by. Just my thought on how the "system" works.
The seal
The collar
Two o rings, on the H anyway
The sprocket
The snap ring
The reason for the two o rings is to preload the collar. So, if the new sprocket you put on is thinner even by just a little the collar will not have the preload on the o rings and let the oil seep by. Just my thought on how the "system" works.
- KDXohio
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Re: Oil leak behind sprocket
Well hmmm... I had to go check the parts diagram I am intact missing the two o rings they must of dried up and broke off or the previous owner got rid of them.
THANKS!
THANKS!

1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Re: Oil leak behind sprocket
There may be just one on the 1989 - 1994 models. Check the microfiche (parts diagrams) at kawasaki.com.
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- KDXohio
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Re: Oil leak behind sprocket
Looked on my local dealers site it shows 2 sitting right behind the colarJason wrote:There may be just one on the 1989 - 1994 models. Check the microfiche (parts diagrams) at kawasaki.com.
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Re: Oil leak behind sprocket
OK, it must be the 1986 - 1988 models. Thanks.
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Re: Oil leak behind sprocket
Is it one or two? Are you guys messing with me?

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- KDXohio
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Re: Oil leak behind sprocket
diagram shows two and parts list under diagram confirms 2 required
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
- KDXohio
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Re: Oil leak behind sprocket
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
- rbates9
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Oil leak behind sprocket
Regardless of if there is one or two the theory of it all stacking together and putting pressure on the o ring to seal it to the shaft still is the same. Maybe they changed to two o rings to help fix a leak? to have two is somewhat showing that there is a spacing issue. If you look at the collar there is only room for one to fit in the grove. But again, this is just the way I see it working and I could be wrong.
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Re: Oil leak behind sprocket
I have the same problem. I found a small crack in my collar that runs the entire length. So i ordered the 2 orings, collar, and oil seal. $40 total. Let me know if you use just one or two. If its is made to have 2 it all should stack together nice correct or is pressure needed to be applied to make the seal? Basically if anyone has done this before let me know the process!
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Oil leak behind sprocket
So i got 2 o-rings and installed 2 and they seem to be working well! No leaks so far.
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Oil leak behind sprocket
2 on my 90' and still looks like it's weeping.
Jeff Fredette looked at it and said it was coming from the flywheel cover

Jeff Fredette looked at it and said it was coming from the flywheel cover

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- bufftester
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Re: Oil leak behind sprocket
If you have oil leaking out of your flywheel cover you have lots bigger issues.
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Re: Oil leak behind sprocket
Good point.bufftester wrote:If you have oil leaking out of your flywheel cover you have lots bigger issues.
He pointed towards it but didn't say that. :hmm
I should find our just what's going on eh?

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Oil leak behind sprocket
Funny enough I have just had my engine rebuilt (all new genuine Kawasaki seals/gaskets etc) and when I took it for an MOT test I had a leak from the output shaft. When I took the sprocket off to have a look it seemed loose on the shaft as though it wouldn't be giving any preload on the collar. I originally thought the engine builder had damaged the new seal but after reading this thread wonder if I have a problem with the collar/O-Rings.
Can the collar and O-Rings be replaced without removing/replacing the seal?
I had run the bike in over the fields with no problem but after the journey to the MOT test station and leaning the bike over on the sidestand the leak appeared. When the engine is not running and the bike is upright it does not leak but with the engine running and the bike upright, oil leaks and builds up on the shaft .
Thanks in advance,
Andy (UK)
Can the collar and O-Rings be replaced without removing/replacing the seal?
I had run the bike in over the fields with no problem but after the journey to the MOT test station and leaning the bike over on the sidestand the leak appeared. When the engine is not running and the bike is upright it does not leak but with the engine running and the bike upright, oil leaks and builds up on the shaft .
Thanks in advance,
Andy (UK)
- rbates9
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Oil leak behind sprocket
Yes you should be able to slide the collar right of the shaft and use a pick to get to the o rings. The collar goes bad quicker then the seal I think.
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