Jump to content
Sign in to follow this  

YZ125 ring end gap?

Recommended Posts

I have a 2014 YZ125 and the Manuel says that the ring end gap should be .019 to .026 thousandths of an inch. I'm replacing my top end with a wiseco racers choice top end kit and the instructions only call for .004 per inch of bore on the ring gap. The bore is just a little over 2" and according to the wiseco instructions the ring end gap should be about .009. So my question is which measurement should I go with and why is there such a large difference in the recommended settings? Also when I checked the wiseco ring it was gapped at exactly .009. Thanks for any insight.

Share this post


Link to post
Share on other sites

Thanks HBR.

I called wiseco and they also recommended that I stay with their specs of .009/.010. But due to myself being very impatient I gapped it last night to the factory yamaha specs. Too much gap is better than not enough. Time will tell whether I made the right choice or not.

Share this post


Link to post
Share on other sites

Yes, you should have followed the wiseco specs.  What does wiseco specify as the service limit?  If it is already beyond that, you should order a new ring now.  A ring is only like $12, and all you need is the base gasket (you can probably slide the barrel off without removing the head.  If it is not beyond the service limit, ride it for a while, and then install a new ring.

Share this post


Link to post
Share on other sites

Thanks for the help guys! After researching this some more I figured out what the problem is.... In the Manuel it gives the spec in millimeters not in inches and that's where I got off. Ordering a new ring and base gasket now. Lesson learned for today

Share this post


Link to post
Share on other sites

Ok guys I got home and double checked my manual and I was correct in trying to gap the ring at .019" to .027" per the manual. I'm not sure why yamaha recommends this large of a ring end gap because all the information that I have found online says .004" gap for every inch of bore diameter. This is with cast and forged piston companies. Anyway I just figured I would share what I had learned today. Patiently waiting for new ring to arrive.image.jpg

Share this post


Link to post
Share on other sites

Ok guys I got home and double checked my manual and I was correct in trying to gap the ring at .019" to .027" per the manual. I'm not sure why yamaha recommends this large of a ring end gap because all the information that I have found online says .004" gap for every inch of bore diameter. This is with cast and forged piston companies. Anyway I just figured I would share what I had learned today. Patiently waiting for new ring to arrive.attachicon.gifimage.jpg

Next time order a TiN ring from wiseco, they dont wear at the exhaust bridge near as much as regular rings.

  • Like 1

Share this post


Link to post
Share on other sites

That is the one I had and re-ordered. It comes standard on the Racers Choice GP piston. $34 Yikes!!!

Share this post


Link to post
Share on other sites

Yes, you should have followed the wiseco specs. A ring is only like $12, and all you need is the base gasket (you can probably slide the barrel off without removing the head.

Thanks for the tip! Worked great and I got it all back together. Ready for the weekend.

Share this post


Link to post
Share on other sites

FYI they're on amazon for $27.30 shipped for the TiN rings.

Share this post


Link to post
Share on other sites

FYI they're on amazon for $27.30 shipped for the TiN rings.

Thanks for the tip. I paid twice that with shipping from wiseco.

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

Reply with:

Sign in to follow this  

×