2014 yz450f oil leak !

I have a 14' yz450f with 78hrs on it i rode it friday night and parked it in my garage. Next day noticed there was oil on the ground and uppon further inspection it looks like my sproket shaft seal is leaking... Im wondering if i have to split the cases to fix this or if i can just pull the sproket and get to the seal. Had me curious so i looked around for anyting else and it looks like coolant is coming out of the water pump weep hole!! WTF.

Any advice with these repairs will be helpful like which parts to order ect. Thanks!

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that seal is an easy fix, just pull the sprocket and the cover behind it.. the seal is right there.. I had the same leak and did not catch it, destroyed my head.. 

The transmission is pressure fed by the same oil pump as the engine.  Oil leaks from the pressure circuit can drain the system of oil with surprising speed.  

 

Examine the exploded view: There is a collar on the output shaft that has an O-ring under it that is "probably" not leaking.  The O-ring is cheap enough, but the collar can be a pill to get off, then you have to hook the O-ring out with a small pick.  You can leave the collar in place unless it has a groove worn into it where the seal rides.  If it must be removed, start by placing the end of a punch in the center dimple of the output shaft and tapping it in toward the center of the crankcase a little bit.  It will only move so far, but this will "unstick" it from the O-ring, and then, with the bike in gear, you can grab it with pliers and rotate and wiggle it out.

 

The second caveat is that the seal pocket does not have an inner lip to stop the seal as it is installed, and so it can be inserted too far and/or at an angle other than square with the shaft.  The seal should stand about 1-2mm high out of the bore, and even all the way around.  

Ok thanks guys! Kinda bumbed this happned but glad i caight it before it dumped the oil out.

You should replace the sprocket spacer/collar while your in there. The seal will cut a groove in it eventually. I've had just as much luck with the All Balls c/s seal kit as oem parts. I end up having to replace mine around every 80 hours as well.

Mud is what does that.  I've only had to replace one on one of 4 bikes once.

Mud is what does that.  I've only had to replace one on one of 4 bikes once.

 

Yup mud is what got me..bike was covered in mud so the leak went unnoticed until i was WOT and it felt like the brakes just slammed on. no oil got to the cams and they dug right into the head, bike would still run but the damage was done. I washed the bike and started it when it was clean and right away oil was dripping out from that seal and at a pretty good rate. That was an expensive repair for a cheap seal...  

Edited by Drenmaster

Do i have to worry about the coolant mixing with the oil with the weep hole leaking?

It's so unlikely as to be considered impossible.  There is an air gap between the two seals that leads to the weep hole, so unless some exceptionally unusual and unlikely things were to happen before it leaked coolant, it would not be able to push its way past the oil seal into the sump. 

 

Read: http://www.thumpertalk.com/topic/841710-04-450-coolant-leak/

Got it thanks!

Son still at Pendleton?

Nope.  He's out.

Nope. He's out.

well hope hes doing well!

:thumbsup:

 

Semper Fi

Do they still do Semper Ride at Pala?

Nope. Its died dow alot for dirtbikes . im trying to get involved and get some things going again.

That Sucks!! Talk about getting a hook up! Getting out of work to have Grant Langston and David Pingree watch you ride and give you tips. I remember the offroad course being mandatory for us in 3rd MAW but that was back in 2009.

That Sucks!! Talk about getting a hook up! Getting out of work to have Grant Langston and David Pingree watch you ride and give you tips. I remember the offroad course being mandatory for us in 3rd MAW but that was back in 2009.

theres all new contractors. dirt bike training is still mandatory every 3 years and i had to track down the right people and then i had to get enough people to attend the class for them to even do it.. . but you dont learn a thing you go around some cones in a dirt lot.. Ticks me off all the street riders get the training. Not like jumping 100ft is dangerous or anything!

I know you guys have heard this, but most of the public hasn't: The U.S. Marine Corps looses more men to traffic incidents than in combat.  That of course is partly because they're really, REALLY good at combat, and kinda crazy while they're off the job.

Sure not hard to believe if you've ever driven around in North County San Diego.

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