oil comming from front sprocket.

What kind of problem might this be. I am hoping just a leaky seal. Has anyone had this problem before? Thanks for your help.

Chris L. :)

Chris, I had this problem once.

It came from running my chain too tight.

You just have to replace the seal. Its not hard at all. :)

do you have to pull the engine? Or just take off the front sprocket and ththere it is?. It doesnt seem to be leaking much. Is this something you can ride on or something you should just fix right away? :)


Chris :D

i had this problem too. all that is wrong is the seal around the shaft (that the front sprocket goes onto) is leaking. behind the front sprocket is a cap. take this off and u will see the seal. it's tight but pull it out and replace. your local dealer probably has it in stock. have fun.

Just be sure to clean the area REAL good before putting the new seal in. You dont want any grime in there to make it leak again.

Push the seal in evenly all the way around. Its about a 10 minute project. Good luck.

I had this same problem with a previous bike. I purchased a new seal and installed it right behind my sprocket, but I when I removed my sprocket I noticed it (the sprocket) was loose. I believe that was the cause of the leak but I replaced the seal anyway.

yea i just replaced the sprocket and chain and that is when it happened. I looked up on parts fish and found what i have to take out. Thanks guys for your help. I should be able to get it. The dealer did in fact have the part in stock. Wahooo :)

The nut that holds the sprocket on is also the nut that

causes the seal to get enough pressure to seal up correctly.

If you didn't replace the tab washer when you replaced the

sprocket (many people don't) it could be that you just didn't

get the sprocket tight enough due to "wrinkles" in the washer.

I've had this happen to me and all I had to do was replace

the washer and retorque the nut..


Just this past Sunday we were out riding in the Ocala National Forest. While I'm putting gas in the bike, one of my buddies point down and tells me I have oil pouring out of the bike. :D (It wasn't even running.) Sure enough, it was gushing out like a stuck pig. Long story short, I had picked up a very hard wood stick just bigger than a pencil and it had lodged in between the sprocket and case. Since I had a stock front sprocket, the stick had worn down the hard plastic ring and that and the wood worked their way into the little gap between the oil seal cover and the shaft and ate a hole right through the rubber oil seal. I was finished riding for the day. Just before they headed back to the trucks, the guys I was riding in front of realized that they were covered with a fine spray of oil that must have been sent airborne from flinging off the chain. :) Luckily, the gas station had a bar so I was able to park myself there for a few hours while my buddies worked their way back on the 35+ mile one-way trip on their bikes to get the truck and come back and pick me up. :D

All I had to do was get a new $7 oil seal, pry out the old one and install the new one. The leak must have only been going on for a few minutes because it had well over a quart of oil still in the motor. The back of the bike was covered with oil and grime so the cleanup was a pain in the ass.

BTW, the oil seal isn't held in by the pressure of the countershaft sprocket nut. There's a metal cover held on by 2 bolts that goes over the oil seal and keeps it in place.

I had a friend that had this problem on his XR500....he left it alone and referred to it as his automatic chain lube system. :D:)

well hell i knew i could screw up a good thing. Well i dont know what i did wrong but i put the new seal in and well i took my bike for a spin and well it was just gusshing out. SO is the seal supposed to be flush with the outter rim or is it supposed to sit all the way back in there. I am assuming nice and flush. Cause i did the other. Any feedback on this. I could use the help. thanks guys.

Chris :)


I would assume it should sit as fap back as possible but I can not say for sure with 100% accuracy. I changed mine a couple years ago so I really dont remember.

What caused the seal to go bad in the first place? Was the chain too tight? I never did hear you say. :)

nope the chain was not to tight at all. I am sure of that. It just started leaking. I am now wondering if i dint get the collar in correctly.

> BTW, the oil seal isn't held in by the pressure of the countershaft sprocket nut. There's a metal cover held on by 2 bolts that

> goes over the oil seal and keeps it in place.

My bad.. my experience was with a 98YZ and I assumed they were

the same. Thanks for the correction..


Got it. I pushed the seal all the way back. But it was only supposed to be flush with the case. Not back to the bearing. So that is cool. I know know how to fix it correctly. But i got an xtra seal this time . Whoo Hoo.

Chris :)

If it still leaks after you put the new oil seal in, make sure the o-ring around the countershaft is still intact. It might be leaking due to that.


OH I SEE the where the O ring goes. thanks for the tip.

Chris L.

I also replace the sprocket spacer along with a new CS seal, the corrosion and scratches on its od usually where the cause of the seal failure in the first place.

I also will help out the little o ring under the spacer by lubricting the splines on the cs with some silicone before installing the new spacer and o ring.

well good news. I am back. Sweet. IT is not leaking at all. I checked the o ring and it seemed to be just fine. It feels good to finally be able to skip out on the 50 shop rate and do it your self. Just letting you know it got it fixed. Now on to fishing and camping in the rain tonight. Should be fun. Will be to liqured up to know.

Chris :):D :D

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