YZ400F doin work...

Ok i bit the bullet and busted out the manual, some may remember my apprehension to doing the work on my own bike having never done it before. well, i decided to check my own valve spacing, and it was easier than expected. i want to make sure i did it right and im not gonna replace the shims incorrectly. I used the feeler guages and found the actual spacings to be way off. the actual measurements are at home but what i really need to know is how much resistance should i feel when i take the measurements? the manual says "some resistance" i went with the minimum resistance i could feel, like started with the smallest feeler and moved up till i felt resistance between the lobe and the lifter. is that correct? if so good deal now i can move on. i have not pulled off the cams yet to see the actual shim size thats installed yet cuz im a little unsure about how to get the timing right once i put everything back together. The book says to make a metal tool for the cam chain tensioner to reinstall it, is that necessary or is there a way around this? also, do i need to take the chain tensioner off all the way to get the chain off the cams or can i loosen it and then tighten it back up once im ready? i guess what im asking is what is the easiest way to get the cams off and do the shims and get the timing right once im done? if anyone can give me a few pointers that would help alot! thanks!:worthy:

Your feeler measurement is just the last one that actually slides into the gap...There won't be a whole lot of resistance, but you won't be able to fit the next size up...

You're going to want to remove the tensioner, and the whole job of getting the chain back on correctly and setting the timing is easier if you remove the ignition cover as well...and be very meticulous about making sure you keep track of which valve lifter goes where, you don't want to mix those up...

...(I) started with the smallest feeler and moved up till i felt resistance between the lobe and the lifter. is that correct?
That' just about it, yes.
Your feeler measurement is just the last one that actually slides into the gap...There won't be a whole lot of resistance, but you won't be able to fit the next size up....
The trouble is that you can get the next bigger size in. In fact, if you push hard enough, you get the the next three sizes in, but that will have more than "some" resistance.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now