Sign in to follow this  
Followers 0
rickmancc

98 yz400f motor done?

6 posts in this topic

I have a 1998 yz400 f I just picked up not running, I found the oil is gray and the anti freeze low, also the exhaust was full of black gas. I searched the forum and looks like I have a grenaded motor, has anyone run into this?

Share this post


Link to post
Share on other sites

To me it doesnt sound like the motor is blown, but instead, these are all signs of a blown head gasket, aside from the black gas. Coolant in the oil is a head gasket prob. If I were you, I would tear the motor down and replace the base and head gasket. And while your in there replace the cam chain and look for any other worn parts to replace. Hope this helps.

Share this post


Link to post
Share on other sites

Also check your water pump seals. I drained my whole cooling system into the oil in less than 4 minutes of running. Both seals were gone and the water pump impeller shaft had a groove in it. I was told that water in the oil due to the WP seals was not likely, but it was what caused it. Just an idea.

Share this post


Link to post
Share on other sites

i own a yzf 400 check the compression if that is good look for a blown head gasket but it should still run if it has a blown gasket. next clean the pilot jet these bikes the pilot jet plugs up real easy.

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