Top End Power Lost After 450 Cam Mod

23 replies to this topic
  • DigilubeJay

Posted January 11, 2006 - 07:34 AM


I also found that bump starting was every bit as easy as a 125 2cycle. It really did make a different bike out of it.

I find it hard to buy off on ring seal making such a dramatic difference in the charector of this modification. Of course if you are afraid that you are gonna choke half way through stroke, and get your shoulder dislocated...and never actually tried to start it by hand 'cause you be skeered (lol)...then I can see where one would have the perception of it being a hard task.

The recommendation for shim change size is a guideline. It is intended to give you a window of what size shims you should probably have on hand when you start the change out.
It is assuming your valve lash is set proper within specs. to begin with.
If all you did is install shims that concur with the recommendations, you need to go back and go through the valve lash procedure properly.

  • grayracer513

Posted January 11, 2006 - 07:49 AM


I also found that bump starting was every bit as easy as a 125 2cycle. It really did make a different bike out of it.

Other than the fact that it's somewhat more difficult to get rolling than a 125, that is true. And that comes in very handy if you kill it with the brake entering a turn. Instead of the "think fast" routine of pulling the clutch, pulling the release, letting the clutch out, get the engine turning, and ease off the release (but watch that throttle!), all before you come to a complete stop, a simple snap of the clutch will get the engine back up, if simply letting off the brake doesn't do it.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • dirttrack25

Posted January 11, 2006 - 01:29 PM


Alright, I took a closer look at the pictures of the cam installed properly...I noticed that the front 9 o clock mark was higher than the 3 o clock. Last time I changed timing I think i timed it opposite of that...So i guess timing is off...1 tooth advanced....Back to the shop i go.

  • dirttrack25

Posted January 11, 2006 - 02:54 PM


WooHOO, I hit the spot that time. I can say that I'll NEVER have a sore foot again. The timing was def. the problem runs awesome now, everyone is right it really does smooth it out, and I love it. Thanks for all the help guys!

Related Content

WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 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

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride

Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 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.