Sign in to follow this  
Followers 0
yamarider426

? on lifter pad selection need advise!

6 posts in this topic

This is my first time adjusting valves on a thumper so bare with me.

I have a 00 yz426 that I bought from the original owner (who barly rode it)and I wanted to make sure valve clearance was in speck. All three intakes were at .005 and both exhaust were at .007. The intakes had #179 pads on outside valves and 175 in the center. My shop manual on a '01 426 says (according to chart) to replace the 179's with 175's. What I dont understand is; From what I hear the valves tend to get tighter and if the speck tolerances call for between .010 and .015 by installing what the chart says I will theareticly be at .09. If I went to 170's I will at .014. And on the center one should i go with the (called for 170, or 165. to put me at .015. I guess the main question is is it better to be on the high end or low end of specs?

Thanks in advance for advise! :banghead:

Share this post


Link to post
Share on other sites

Just make the proper change to get the valves in spec. You are talking about 5 hundredths of a millimeter, that is very small. .09 is out of the proper specs .14 is within the specs. Go with the 175 to get the outside intake valves to the proper clearance. Your goal should be to get the valve clearances within specs. So measure the clearance when the motor is completely cold. I usually wait overnight before I check them. If the intake valves are in the range, don't mess with them. if they are off, follow the chart in your manual. The pads you buy are usually sold in 5 hundredth increments so a 175 is "5 hundredths" larger than a 170 pad. Since the range is from .10-.15mm you don't really have many options. If the valves are within that range you are fine. Hope this rambling helped! Matt

Share this post


Link to post
Share on other sites

You're mixing your measurements here, and if I try to answer based on what you've written, I'll be guessing what you meant.

Measurements taken in metric units should be in hundredths of millimeters (.01). You are writing 3 decimal places as if your measurements are thousandths of an inch (.001). Please clarify which units you're using and correct them so we can be more accurate.

For example, if your intakes are at .005", they are perfectly in spec at .13mm, and should not be changed.

A 175 shim is 1.75mm thick, .05mm thicker than a 170 (1.70mm)

Share this post


Link to post
Share on other sites

Good advice Matt!

FYI... Yamarider, you can buy a shim refill kit from the TT store for $35 and it'll contain a whole slew of shims in varying sizes. I got the 1.80 thru 2.05 range and it's more than paid for itself. My dealer wants $5/shim, the kit has 21 shims (I believe) for $35.

Here's the P/N's if your interested:

http://img.photobucket.com/albums/v420/BrandonV/s2_949.jpg[img/]

Share this post


Link to post
Share on other sites

Measurements taken in metric units should be in hundredths of millimeters (.01). You are writing 3 decimal places as if your measurements are thousandths of an inch (.001). Please clarify which units you're using and correct them so we can be more accurate.

sorry Yamarider. I meant hundredths of millimeters not thousandths.

Share this post


Link to post
Share on other sites

Thanks guys

I ment .07

I went with the 170 pads on the intake and they came out to .10

so I guess Im good to go

I also did the bk mod

I loooove that !!!!!!

bike runs great

thanks for the help!

Share this post


Link to post
Share on other sites

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
Sign in to follow this  
Followers 0