07 YZ450F Cam chain

41 replies to this topic
  • kebin

Posted February 18, 2011 - 06:45 PM


This is my 1st post. I have a 2007 yz450f that I was riding when it just stoped on me, felt like it lost all power. I Opned up the valve cover to check the timing and the intake cam spun on the sprocket and made the intake vales hit the piston. The chain did not jump because it was a TDC and the timing markings were correct. I looked at the otherside of my bike to look at my lobes that were facing out like they should but only my exhaust lobes were correct witch was at 2o clock. My intake lobes were at the 9o clock position when it should be in the 10o clock. Since the intake sprocket spun it made my springs work extra hard witch broke one of them causing no compression. my fix is buying a new cylinder since it was scratched, new piston, intake valves, springs, seals and 2 new cams. to never have this happen again I will be tigging the sprocket to the cam since its only pressed on. hope my hardship helps you.

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

Posted February 19, 2011 - 08:06 AM



When viewed from the LEFT side of the bike (the ignition/timing mark side), the exhaust cam lobes should be pointing at about 9 or 10 o'clock, and the intake cam lobes should be at about 2 or 3 o'clock, approximately. Basically, the exhaust points to the front of the bike, & the intake points to the back, with the piston at TDC. But the important thing here is that the timing marks are all lined up as they should be.

Also, check before you TIG the cam sprocket to the cam. that could (and most likely would ) screw up any hardness ratings/heat treatment the metal would have after heating it that much..... I do realize TIG focuses the heat in a small area, but I'd still be a bit leery about welding the sprocket to the cam. Seems like that's a sign of a bigger problem, actually..... :smirk:


Related Content


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

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

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

YZ450F 03 Sparks driving me crazy by SirAttard

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