HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
412MotoRob

In need of some help!

9 posts in this topic

Just replaced the outer seal on a 2005 yz450f water pump because it was leaking, changed the seal started it for about 15 seconds & it didn't leak, then proceeded to take it up & down the street a few times & when I went to park it I realized it was leaking fairly steadily....& then I let the bike cool for a few mns and then I let it idle for probably 30 seconds & it wasn't leaking but I can't run the bike anymore cuz my yoshimura exhaust is too damn loud & it's getting late & now I'm like wtf.. & no the seal is NOT in backwards & my shaft is not grooved. So here's my question, does a new seal need to "set in"? Or do I have another issue?!?

Share this post


Link to post
Share on other sites

Did you inspect the shaft for wear?

The seal can only seal if the shaft is perfect.

there's marks all over where the old seal was but I can't really feel anything?

Share this post


Link to post
Share on other sites

One thing to look at is the balancer shaft bearing.  The inner end of the shaft is supported by the balancer shaft.  With the right side cover off, check for vertical play in excess of .006".

 

Your seals are oriented as shown here? 

 

SealsLabeledsm.jpg

1 person likes this

Share this post


Link to post
Share on other sites

One thing to look at is the balancer shaft bearing. The inner end of the shaft is supported by the balancer shaft. With the right side cover off, check for vertical play in excess of .006".

Your seals are oriented as shown here?

SealsLabeledsm.jpg

not really sure how to check but I guess I'll just wiggle it around and see if there's play? & it doesn't leak right away, it takes a good 30 seconds of idle and a slow drip will start. & if the balancer bearing is shot is that easy to replace? But I think it very might well be just the shaft, I could see marks all over where the old seal was but I didn't really see any scoring, I should probably feel it to make sure it's smooth. & how sensitive are these shafts to leaks?

Share this post


Link to post
Share on other sites

The shafts are really fussy.  Roughness and scoring in the sense you probably think of either one are well beyond what it takes to get one to leak.  Anything you can feel by dragging a fingernail over the surface is probably enough to cause trouble.  Looked at another way, if you can't polish the marks off in a few minutes with 320 grit, it's bad.

 

The balancer shaft bearings in the '03-'05 Gen1 450's require the cases to be split to replace them.  The Gen2 ('06-'09) can be done in the bike, but it's a challenging procedure, and not for the marginally skilled.  The link below may also work for the later Gen3 & 4 engines, but I haven't researched that.

 

http://www.thumpertalk.com/topic/1059507-07-wr450-help/?tru=GKvpN#entry11302329

Share this post


Link to post
Share on other sites

The shafts are really fussy. Roughness and scoring in the sense you probably think of either one are well beyond what it takes to get one to leak. Anything you can feel by dragging a fingernail over the surface is probably enough to cause trouble. Looked at another way, if you can't polish the marks off in a few minutes with 320 grit, it's bad.

The balancer shaft bearings in the '03-'05 Gen1 450's require the cases to be split to replace them. The Gen2 ('06-'09) can be done in the bike, but it's a challenging procedure, and not for the marginally skilled. The link below may also work for the later Gen3 & 4 engines, but I haven't researched that.

http://www.thumpertalk.com/topic/1059507-07-wr450-help/?tru=GKvpN#entry11302329

I really appreciate the help man, & I can actually feel 2 distinct notches where my finger nail gets caught now that you told me that, I didn't know the shafts had to be that spot on?? But hey I guess it's a good thing I bought extra case gaskets I'll update this when I get the shaft.
1 person likes this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0