Wiseco Piston

4 replies to this topic
  • sanpedro426

Posted January 20, 2005 - 11:27 PM


Im getting ready to do the top end of the ole blue beast :cry: and the thing that paeked my intrest is the oil ring set. It doesnt seem like the oil rings are going to go in properly. It seems as though the center part of the oil controle ring is too big and will NEVER compress enough to go in. Has ANYBODY used a wiseco piston set in there 426. I have cross checked the wiseco #s and everything matches. I dont even think a ring compressor will get the job done without damaging the ring (couragated ring). ANYBODY :cry: :cry: :cry: :cry:

  • mayday

Posted January 21, 2005 - 03:17 PM


Hey I just put a wiseco piston in my 02 wr426f. You just got to play with it. I thought the same it seemed that the s shape oil ring was to big. It is a pain but you will love it in the end! also double check you valve shims before you put it back together again. Mine slipped out of there grove and caused a no compression condition took 3 days to figure out. I must have check my timing 7 times before I checked them Hope this helps

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • sanpedro426

Posted January 21, 2005 - 09:31 PM


Thanx , did you NEED to use a ring compressor like the directions said on the ring package? :cry:

  • Wayne_Thompson

Posted January 21, 2005 - 09:33 PM


Had the same problem with mine a couple of months ago. Turned out they were the wrong rings for the piston. I will never use Wiseco again. Only OEM

  • grayracer513

Posted January 21, 2005 - 10:54 PM


The "triplex" style of oil ring is always more difficult to compress by hand than the compression rings are.

Be sure they are assembled properly. Check the manual for the locations of the end gaps. If you don't have one, if the center intake valve is at 12:00 o'clock, the expander end gap should go at 10:00, and the ring ends at 8:00 and 4:00.

Make sure that the expander ends are butted, not overlapping, and the both rings sit on the expander correctly. Lube the rings and the bottom of the cylinder liberally with clean engine oil and work the cylinder down over the rings. You can put a rag over the crankcase mouth and set the piston skirt on it for support, then bump the cylinder with the heel of your hand to help it on, but be careful doing that.

A ring compressor does make the job easier.

Related Content


2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

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.