First 4 stroke yz426

4 replies to this topic
  • justinpage426

Posted February 15, 2016 - 11:59 PM


Well I picked up my first 4 stroke dirtbike and it skipped timing so I tore it apart and the engine would still turn over freely but the cam chain was bad and had some links seized on it. Replaced the cam chain and reassembled but when I got the timing set i tried to turn the motor by hand and when the camshaft lobs touch the valves it just stops moving and won't rotate. I haven't put much force on it at all. So I'm stuck and can't figure out why it's doing that. Could it be from not having the tensioner in? Or from turning the motor over several times after having the cam chain and cam shafts off it. I'm just stuck and can't figure this out. It's an 01 yz426.

  • grayracer513

Posted February 16, 2016 - 07:07 AM


Could it be from not having the tensioner in? 




Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • justinpage426

Posted February 16, 2016 - 12:00 PM


Ok going to try and put the tensioner in and see if the camshafts will roatate
Ok going to try and put the tensioner in and see if the camshafts will roatate

  • grayracer513

Posted February 16, 2016 - 12:08 PM


In order to install the tensioner, you must back it all the way off and lock it there, then bolt it in place, then unlock it.  The center tower part of the tensioner has a 10mm hex bolt in it.  Remove this, then use a small screwdriver on the tensioner screw to retract the tensioner plunger.  It should stay in place like that if you get all the way to the end of the travel.  Once in place, use the screwdriver again to fudge it back forward until the spring takes over.  Then replace the center bolt.


Download a manual:


  • justinpage426

Posted February 18, 2016 - 03:20 PM


Thanks it was the problem

Related Content


Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies

First Hare scramble tips by dhend8

Dirt Bike   General Dirt Bike Forums   General Dirt Bike Discussion
  • Hot  33 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

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.