valve shim question/help



13 replies to this topic
  • treefrog

Posted March 26, 2014 - 06:58 PM

#1

99WR400f-Just got through checking my valve clearances and I think that I am just confusing myself. I know it is pretty straight forward to figure out shim size but could some one give me a hand and help me figure out what size shims to buy please?? :banghead:

 

-READINGS ON MY BIKE

 

EXHAUST #1=.254

EXHAUST #2=.229

INTAKE #1=.127

INTAKE #2=.127

INTAKE #3=.127

 

-BOOK SPECS

 

EXHAUST 0.25-0.30

INTAKE 0.15-0.20

 



  • mch

Posted March 27, 2014 - 06:53 AM

#2

If it's anything like the newer bikes, there are "pads" or shims.  You cannot ask what size to buy based on the information you provided.. well, I guess I can say buy a shim hot cams shim kit.  If the tollerances are too tight, you take off the current pad and go with a smaller one.  Until you see what size pad is in there, you won't know what pad to replace it with (they are all different sizes).  It's simple math once you see what the old one is (you may want to mic both of them too) and determine what you want the gap to be.



  • grayracer513

Posted March 27, 2014 - 07:37 AM

#3

The #1 exhaust needs nothing.  All of the others need a shim one size smaller (-.05mm) than what they currently have in them.  As stated, you can't know what size might currently be in place until you see them, and they are all apt to be different.  Usually, you can "shuffle" them around and adjust 4 valves by using two old shims and two new ones. 

 

Service shims are sold by Yamaha in increments of .05mm (.002"), and are marked by their actual size (180, 185, etc.  185 + 1.85mm) If the engine has never had a valve adjustment (don't think for a minute that's not possible), or has been adjusted by a shop tech who used used shims from his collection, you may find shims marked in odd sizes like 178 or 182.  These are original factory shims available in .01mm increments, provided only to the original assemblers.

 

Remember that the whole specified range is only .002" wide, so don't obsess about where within the range your clearances end up as long as they are within the range.



  • treefrog

Posted March 27, 2014 - 09:46 AM

#4

so I find out the shim thickness for each valve that is out of spec and add what is needed to get within spec. That will give me the total thickness of the shim that I need correct?


Edited by treefrog, March 27, 2014 - 09:51 AM.


  • treefrog

Posted March 27, 2014 - 09:53 AM

#5

will I need to mic the old shims to figure out the size or is the size generally stamped on the shim?



  • William1

Posted March 27, 2014 - 10:05 AM

#6

If the valves are tight (clearances LESS than the book specifies) you need to use a thinner shim.

I mic all shims, irrespective of the marks.



  • flyandride

Posted March 27, 2014 - 10:19 AM

#7

You own a WR so it's time to pony up for a shim kit.  Look on ebay.  It's just simple math to figure out which shim to use.  Sometimes the numbers get worn off, a micrometer helps.  I've compared 2 with a magnifying glass to figure out one with no numbers.  



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

Posted March 27, 2014 - 12:33 PM

#8

so I find out the shim thickness for each valve that is out of spec and add what is needed to get within spec. That will give me the total thickness of the shim that I need correct?

 

I'm just using this for example, but if you have a shim in the motorcycle that is 185, and you need to go .05 smaller, you stick in the 180.  You only use one, you don't put two in like 150 + 30.. 



  • treefrog

Posted March 27, 2014 - 05:45 PM

#9

I gotcha. I meant the overall thickness. I know im not going to stack two shims. I just wanted some clarification before I got any further on the whole process. Seeing that checking and adjusting my valves is going to be part of my regular maintenance, I will be getting the kit to have what I need on hand. Didn't mean to sound like a complete dumb ass just want to be sure I understood the  process before I just went in and winged it. Found a valve shim calculator link that was helpful. I appreciate all the input

http://www.tm-racing...calculator.html



  • mch

Posted March 27, 2014 - 07:57 PM

#10

I gotcha. I meant the overall thickness. I know im not going to stack two shims. I just wanted some clarification before I got any further on the whole process. Seeing that checking and adjusting my valves is going to be part of my regular maintenance, I will be getting the kit to have what I need on hand. Didn't mean to sound like a complete dumb ass just want to be sure I understood the  process before I just went in and winged it. Found a valve shim calculator link that was helpful. I appreciate all the input

http://www.tm-racing...calculator.html

 

Yeah, it seems like whenever I do something on the bike for the 1st time, there is a lot of reading, double checking, etc.  Then after you do it, it doesn't turn out to be as hard as expected.  I didn't find the valve adjustment all that hard, but I had my GF's son put the valve cover, plastics, etc. back on.  Make sure the valve cover gasket is lined up and don't tighten it so it deforms the rubber (you aren't torquing down a head gasket).  Anyway, it was a big oily mess after my ride on it.. so just keep that in mind.



  • JVP

Posted March 29, 2014 - 12:29 PM

#11

Watch the U-Tube Videos on Valve Shim Replacement. You will learn step by step on how to adjust and replace valve shims. After determining what shims you will need purchase them individually through the dealer or better yet Rocky Mountain. Also, don't buy a complete kit. The kits come with too many sizes you will never use. Each kit come in either .05 increments or .025 increments. If you buy them individually you can get the exact size with out the waste.

  • treefrog

Posted March 29, 2014 - 03:30 PM

#12

I pulled my buckets and shims and the numbers on the shims say 188, 178, 184. How does this measure? .188mm? I dont know how to calculate for my new shims. Confused please help

Sorry for the double post. Couldn't figure out how to delete this post and add it to my old one. I think I need a 180 for the 188, 170 for the 178 and 176 for the 184. Does this sound right to anyone?


Edited by treefrog, March 29, 2014 - 04:38 PM.


  • JVP

Posted March 29, 2014 - 07:35 PM

#13

Watch this video!!!! http://www.bing.com/...58FD0A767E2FA91



  • treefrog

Posted March 29, 2014 - 07:42 PM

#14

Got it. Was clear as mud but crystal clear now. Thanks for putting up with my hounding and ignorance :facepalm:






 
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.