YZ400 bogging problem solved!!

No replies to this topic
  • samaki

Posted March 31, 2004 - 05:56 PM


You may have read previous posts concerning a real bad bogging problem with my 99 YZ400. After much time and work I have found the problem and repaired it. The bike works wonderfully now and makes my WR seem tame in comparison.

What I discovered was that the intake cam had spun in the gear approx 20 degrees (40 crank degrees!), retarding my cam timing. As a consequence, compression was low and power output was horrible, plus it had a bogging/dying problem off idle. Though the timing marks on the cam gears were aligned with the top of the head at TDC, the intake timing was retarded 40 crank degrees. I reindexed the cam, heli-arc welded the gear on (exhaust as well)and it is good to go. Thought maybe someone else out there might be experiencing a similar problem.

Thanks to those who posted suggestions and information.

Related Content


Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

Is it worth it? (Cam and High compression piston) by macgi77

Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies

05 yz450f not fast enough by RedeyeYZ

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

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

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.