Finding size of valve shim when the letters aren't readable...

Working on my valve check this weekend. I've got all the measurements except for #3 and #4 exhaust. Took the shim for #3 out and the lettering is faded. I can read Y at the front and 0 at the end. The first two numbers are gone or indecipherable. My other two exhaust shims have both been 270, and I stacked feeler gauges up to 270 and the shim looks like the same size. Is there a better way to do this? I don't have any spare shims, or I would put another one in exhaust #3 and put that shim into #2 where I know what the measurement was with a 270.

Any tips? I unfortunately don't have a caliper, and I thought I read somewhere else on here not to trust them anyways.

For reference:

 

Use one of these.



Not trust a caliper? Calipers are one of the tools that were used to make the engine you are working on. Even the cheap digital calipers that are avalible now have a good enough resolution for accurately measuring shim thickness.

 

I use calipers all the time.

 

trust your digital calipers. check a new penny 19.08 to 19.1 mm (their not exactly round)

 

Ditto, trust you caliper . . . and unflappably trust your micrometer. (You did remember to use a Master on it prior to use didn't you?)

Measuring tools are only as good as your technique using them. Stacking shims/ feeler gauges is VERY subjective and opens up to parallax issues. Using a measuring device with two or more contact points, even if it is a transfer type gauge, can be much more accurate, however, I always follow the "measure twice rule" to verify a repeatable result. Even the best measuring tool has room for error.

 

Thanks guys. Picked up some digital calipers from Lowes and it looks like it's a 260. I will double check the accuracy against a penny though to be sure.

 

Find a shim you can read to confirm and maybe hogfiddles wil know did yamaha use any odd sized ones from the factory as Honda did with the big shims for CB Honda twin cam air cooled bikes bikes I have a bunch of the odd size ones for my 900 custom they are like
Gold

 

I go into a cold sweat and semi-panic mode when I can't find our calipers, or even if the battery is dead.

 

Checked the calipers against a 270 and it was damn close. Ended up that I also couldn't read the #4 exhaust so I pulled #1 which was a 270 and it measured 2.72. I was getting readings of .262 and .263 on exhausts #3 and 4 so those must be 260 shims.

Also, if the shim chart leads me to a blank space, does that mean no adjustment is needed?

Hey Len, I don't see shims on your catalog. Do you sell them? I might also be blind.

 

measure your feeler guages to test for accurary.

 

blank means your good. and len does sell them shims.

 

They can be found on EvilBAY as well. Usually just whatever size the wrecker pulled out of some poor xj, so its pretty random as to what you'll find, but if you were starting a shim bank, that'd get you a bunch of 'em...

 

looks like the shim in your picture has been fitted the wrong way up, its been rubbed off by the cam, numbers should go to bottom.
stu

 

Maybe it was at one point, but it was fitted numbers down when I pulled it. Funny enough, both #3 and #4 exhaust were the same way. No problem reading any of the others.

I looked around but the prices on fleabay were the same or worse than xj4ever, so I just ordered them all from Len like I've been doing for all my other parts. Briefly tried to source them locally to save time, but no one carries shims for bikes this old.

 

I felt guilty mentioning the 'bay, like I was betraying Chacal or something. Sorry , Len... XJ4ever FOREVER!!! There. I feel better.

As for shims for bikes this old, there are other bikes which still use this size of shim. I can't remember which ones, and I'm not gonna try, but if you request ones by size (29 mm shim diameter) you may have more luck then if you ask for ones for an '80-something XJ. Maybe another member could remind us both which modern bikes' shims are interchangeable.

 

after recently talking with a local bike shop, one who seems to be one of the few in the area that will work on older (10+) motorcycles, we started talking valve shims. Knew I would be needing to replace some soon, told him that they were 29mm diameter but also mentioned remembered seeing on here, maybe in the XJ4ever catalog, that the were NOT Suzuki shims. They checked, had some 29mm in stock, but wasn't sure what i meant by not being Suzuki shims. Can any shed some light onto what the difference is. I ended up just getting the shim with the rest of an order with @chacal anyways, but it would be good to know.

 

Suzuki shims have beveled edges.

 

ahh, thanks chacal!

 

Cuz a lot of them are in my shim pool boxes

 

The rest of them are on various shelves around the country. There are plenty of current motorcycles that use 29mm shims (not the majority, but still plenty).

 

Do the non beveled shims fit into XJs, or should we stick with the Yamaha style? I think I saw some aftermarket shims at XJ4ever. Are they beveled as well, Chacal? Was thinking of hoarding some, in case Dave wants more!