valve shim ???

ok i did some searchin on valve adj. cant seem to come up with an answer.

when yu replace the valve shims ..do yu just replace with what was in there to begin with or do yu get a shim that takes into account cam lobe wear....if any.......to get it back into spec.

sorry if this is an oldie......i searched till my eyes were burnin.

thanks



dale

 

Hi mate
You should have two pad selection charts
1 for exhaust
1 for inlet
say you check no1 inlet, you write down the clearance
take out that shim ,on the back is its size,write that down then put it back.
using the intake pad selection chart
read right to left for the installed pad size say 245
read the column on the left down for the clearance say 0.51-0.55(mm)
read across from the clearance and read down from the installed shim size ,where they intersect is the new shim size so the new pad size to be installed should be 285
c ya

 

There is quite a bit of info here on valve adjustment. I cant seem to get the link I am trying to post up to work. Type in valve shim adjustment and go through those. Dang, I wish I knew more about computers.

 

Let see if I can get this to work. There is a shim calculator on this site as well. Good price on shims also. dont worry about the KLR thing. They are the same shims. dual star

 

thanks folks.........great dudes yu are......

 

samsr:

The folks at DualStar are currently out of most sizes, and say their suppliers are out also. Does anybody have other good sources?

Thanks,
Herb

 

I guess we ran them out of shims. Do you know what shims you need. I have a few left over from my valve adjustment you could have. Other than that try sudco. Sudco.com I believe

 

samsr:

Thanks for the offer.

I was thinking today, if enough XJers wanted to participate, we could probably pool and swap our extra shims and meet most needs, unless everybody needs the same sizes!

I NEED a 255.

I HAVE a 260, 265, 270 (2), and 280, if you can use any of those.

Thanks again-
Herb

 

I dont have a 255. I pretty much have the same ones as you do. These Seem pretty common when the valves are adjusted for the first time. Sorry I couldn't help any more than I did.

 

Search the forums for "XJ shim pool". It's been done before. Don't know if they're still doing it or not.

 

good luck finding the shim pool. After a couple of weeks I gave up. But people here are friendly and generally if you ask they will respond.

 

samsr:

No problem - thanks for the offer anyway.

I have one exhaust valve that's just below the acceptable range, so I'll probably just ride it until Dual Star gets some more shims in stock.

Stay safe-
Herb

 

When I got my updated set of XJ cds, one of the bits on there was a recap of various "Carb Clinics", and at least two of them made note of the fact that Brad Bowen (who distributes the cds in our neck of the woods, if you'll recall) had brought the shim pool...

 

I went through the valves on my 80 xj650 2 weeks ago. Found I needed 6.
Went to the local Yamaha dealer, the parts guy checked with the mechanic and he had a box full of them.
He let me swap mine for the ones I needed for nada.

Good Luck,

 

so are yu guys actually replacin the shim with stock size???

i would like to doo my whole head just to get it outta the way....can i just replace em all with the same as what are in there now???

i just dont get it i guess???????????/

 

mr_ex, the shims don't wear out, it's the other parts of the engine that change, mainly the valve changes.

You need to check the valve clearances on each valve with the cam lobe directly opposite of the valve your checking. Once you get your reading ( if it’s not within spec ) you have to know which shim is currently in that position. Then you look up the known values ( current shim size, current valve clearance, intake or exhaust valve ) on a chart and that tells you which valve shim you need in that position to get back within factory specs.

Valve clearances on a COLD XJ700N / NC engine should be:
Intake 0.11 ~ 0.15 mm ( 0.0043 ~ 0.0059 in )
Exhaust 0.16 ~ 0.20 mm ( 0.0063 ~ 0.0079 in )

You may be able to swap your current valve shims around from one valve to another to make up your adjustments. When I did my engine I only needed to purchase two or three shims, most of them shuffled around.

That's why it's a good idea to have a valve shim chart of what's in your engine at the moment, helps with the calculations when this service is required.

Hope this helps!

 

thats what i was a lookin for......i just couldnt put it together in my head i guesss.....course im not the brightest pickle in the jar :lol:

thanks nick :wink:

think ill save that project for this winter 8O

 

Mr_ex:

You have to measure the gap between the cam and shim (when the valve is closed) with a feeler gauge to check the clearance.

As the valve and valve seat seat wear and the valve recedes into the head, this clearance will gradually decrease. At some point, you have to go to a thinner shim to keep the clearances correct. If not, the cam would eventually be holding the valve open too long (or constantly), causing loss of compression, burning the valve, etc.

My Seca manual recommends checking the shim clearance after the first 5,000 miles, and then every 8,000 miles, if memory serves me correctly (which is rare).

Read up on it in you Haynes or owner's manual, or have an experienced friend walk you through the process the first time. It takes a little time and you have to be methodical and clear-headed, but it's one of those maintenance processes that will help you get to know your XJ better and make you more comfortable handling the bigger issues.

Good luck-
Herb

 

ty herb......i never had a bike with a shim valve system before.
i thought the cam would ride on the shim and the shim would wear.

i looked at a teardown.....now i see how it works.....kinda strange system if yu ask me.

ty for help guys

 

Over time valves can set and cams can wear so the clearances between the cam and valve shim can get bigger or smaller. You have to measure the clearance between the cam and valve shim with a feeler gauge when the valve is closed and the cam lobe is facing away from the valve. If the clearance is too small, valves can remain open when there is combustion and you will burn a valve; if the valve clearance it too large, you get a loud valve train. You have to measure these clearances and replace the valve shims with shims that will restore the proper clearance.

The valve shims are made of hardened steel, do not wear and are reusable. Simply replacing the shims with the current sized shims will not correct the clearances.