valve seal removal '98WR400?

4 replies to this topic
  • toooldforthis

Posted March 02, 2009 - 03:06 PM


Hello. I am doing some top end work and I was going to replace the valve seals (sold as a separate part number). The manual shows how to pound out the whole valve guide with the special Yamaha tool. Does anyone know how to remove the seal only?


  • Birdy426

Posted March 02, 2009 - 05:19 PM


You can grab them with your fingers and just pull them off. if that doesn't work, use a dentist's probe.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • toooldforthis

Posted March 03, 2009 - 06:07 AM


Thanks Birdy.

  • Thermos O flask

Posted March 05, 2009 - 03:08 AM


While your on the subject of valve seals,I'm going to be fitting a high comp piston to my '00 wr400 soon and was wondering if i needed to replace the valve stem seals? It doesn't use a drop of oil.Are they a common wearing item?

  • Birdy426

Posted March 05, 2009 - 03:38 PM


Should be fine if they aren't leaking now. The valve seals seal from the valve cover side to keep oil out of the combustion chamber. The piston pushes the valves into the seats a bit harder wiht a high comp piston, but the vacuum created on the down stroke isn't any greater.


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.