Jumped Timing?

1 reply to this topic
  • joehonee

Posted January 16, 2010 - 02:53 AM


While doing a tuneup on a recently purchased 01 YZ426 I checked the valve clearances and they were fine. When I moved onto the cam timing check however, I ran into a little problem. The intake cam was off 2 teeth and the exaust was off 1. I have corrected the problem but am trying to determine what caused it. Previous owner/mechanic error or is there an underlying issue with the engine. The tensionor operates well.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted January 16, 2010 - 08:50 AM


WHen you did the re-timing, you should have checked the condition of the cam caps and saddles for evidence of the cams having seized, and also for signs of kinking, binding links in the cam chain. Otherwise, it's possible that the cam chain is simply too long, or that the sprocket on the crank axle is worn.

Related Content


The "going back to the other darkside" adventure... by Monk

Dirt Bike   Make / Model Specific   KTM   250/350/450/505 SX-F & XC-F (4-Strokes)
  • Hot  113 replies

BIGBORE FOR YZ450F 2006? by Taattie94

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies

05 yz450f not fast enough by RedeyeYZ

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  38 replies

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 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.