Adjusting Decompression Freeplay


2 replies to this topic
  • jchammer

Posted September 25, 2005 - 08:51 AM

#1

Need some help adjusting my decompression lever freeplay. Just got done replacing my timing chain and reshimming my valves, and it noted that I needed to check for 5mm of freeplay on my decomp. lever. (It was always tight - just never realized I needed freeplay)

I have turned the adjuster in as far as I can get it, but I still have zero freeplay, and it is so hard to turn I'm afraid the threads will strip if I go any farther. I've WD-40'd the hell out of it and it still is really hard to turn.

One thing I'd like to know, though, is freeplay defined as "movement in the lever does not move the decomp shaft" or "movement in the lever moves the shaft, but is still considered freeplay until the shaft actually contacts the valve lifter bucket inside the engine"? I guess I'm ok if it's the 2nd one because I can move it a bit before I feel the shaft contact the valve lifter bucket.

Thanks.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • cowboyona426

Posted September 26, 2005 - 12:48 PM

#2

Make sure the cable is routed properly first off, then you might try moving it around on the bars to get a little slack in it. Or better yet, just buy an 03 YZ 450 exhaust cam and ditch the whole setup! :banghead:

  • grayracer513

Posted September 26, 2005 - 02:37 PM

#3

"movement in the lever moves the shaft, but is still considered freeplay until the shaft actually contacts the valve lifter bucket inside the engine" is what is important here. Free travel here, just as with the clutch, is the motion in the cable that does not activate the device. Free play must be set with the engine on the compression stroke.

However, the free travel should be a one finger deal, and operating the lever no more than two. Double check the cable routing, lube, etc. Also be sure the free play does not change as you turn the bars.





Related Content

Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • - - - - -
  • 0 reviews
Forums
Photo

Michigan Motocross Tires by 288yz450


Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply
Forums
Photo

YZ450F 03 Sparks driving me crazy by SirAttard


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
 
x

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.