Valve shim adjustment problem

[dardoonk]

My bike is a 77 GS650B.
I have an issue adjusting the valves. I've recently rebuilt the entire top-end and have only ridden 10 or 15 miles since I completed the bike. Right or wrong, I had figured that if I put everything back where it came when I rebuilt the head, the valves would be close enough to start-up and I would complete my initial valve adjustment after the valves had time to seat. Basically that is where I am today.

So now I have attempted to check the tolerance on every valve and my smallest gauge, (.0012") will not fit under ANY cam lobe. I pulled two shims and found they are both 2.65mm, so I stuck those back in and checked another--- same thing, 2.65mm.

This lead me into a flurry of questions, that, frankly, I have no answer to...

1] How the heck do I know what shim to use if I cant even measure them?

2] I'm using the compression tool thingy, but cannot depress Intake 2 or exhaust 3 enough to remove the shim. What do I do about that?

3] I have no extra shims smaller than 2.65. I can buy some, but the smallest ones I see are 2.15mm. What happens if I put a 2.15 in and still cannot get any clearance?

4] I need a bunch of small shims.. can anyone help?

btw; yes, I am measuring correctly

[TheCafeKid]

yikes...what position is the lobe in when your measuring? Should be with the point of the lobe UP. you have to turn the crank by hand obviously to do this. Secondly Steve and i had the same probs with the inside cyls. I have a SAFE way to get around this that he showed me, easy as pie but you have to watch whats going on with the cams, so they dont skip a tooth, and you'll prolly want a second hand to help out (get the wifey...all she has to do is hold a screwdriver.)

And, i know you are not stupid...but .0015mm IS SMALLLLLL...you sure thats not inches?? I had to special order a feeler gauge that actually had the correct MM feelers from Z1. .03 to .08 is spec in mm. .0012 to .0031 in inches...if you are using inches, and .0015 wont fit, you may still be in spec.

I'll PM you the lil trick for those inside cylinders in a jiff..got to run an errand real quick bbiaf.

[dardoonk]

Dohhh.... I work metric all day... brain fart.. I'll go back and edit that.

There now, I fixed it but I still got the same problem

[TheCafeKid]

ok well you'll have to give in and find a set that will go down that far, cos obviously those dont. Z1 has them for 7 bucks and some change, go down to .04 mm. If you're that close, i'd change them out. Like Steve was telling me, he'd rather them be on the high side of spec, if not just a tenth over, cos soon enough they'll be beat into spec, and you wont have to change them out as soon as you would if you just get them in the middle of.

PM coming your way BTW...

[tconroy]

bike bandit has some that go to 0.03mm which is as small as you can get!!! Be sure to use mm.It is a lot easier to decipher for me.The guy that helped me did them in inches and we had to start all over!Good thing is i did not start the engine!

[Nessism]

You need a shim in the 250 range so you can get some clearance on the valves and measure the clearance. Once you get the clearance, it's an easy calculation to figure out what shims you actually need. I doubt you will need anything smaller than 250 since you would be loosing a lot of compression and the bike would not run right at all.

Good luck.

[dardoonk]

bike bandit has some that go to 0.03mm which is as small as you can get!!! Be sure to use mm.It is a lot easier to decipher for me.The guy that helped me did them in inches and we had to start all over!Good thing is i did not start the engine!

Okay, they the shims do go smaller than what shows up on the fiche? That's good news, well, at least I feel a better about it.

I was panicking thinking what do I do if my clearances are actually less than the smallest shim I can get.

[TheCafeKid]

he's talkin bout feeler gauges. The shims will go as small as you need them. If they are THAT out of wack that bike would not run at all i wouldnt think.

[Steve]

Have you looked at all your shims and verified that you have none less than 2.65?

Not really unusual, but I have usually seen quite a mix of sizes. You said you did not see sizes less than 2.15 in the catalog. That's OK, because that is 10 sizes smaller than you have in there now. Since you know that you are going to need smaller shims but you don't know what size, you are going to have to make at least two purchases. Order up a 2.60, 2.55 and 2.50. Put one of them in place of any of your current shims and re-measure the clearance. It might be right, it might be loose, depending on which one you use. If it's too loose, you can at least figure out how loose it is and can determine what size shim to use. Record what size you will need for that valve position. Now you will have to put the original (tight) shim back in so you can move the smaller shim to measure the next valve. Money spent on shims is not wasted, as you will likely need it next time, if not this time.

This would also be a good time to offer you the spreadsheet I have developed for tracking your valve adjustments. Part of the procedure for the first adjustment is recording all the shim sizes, anyway, so you are already one up. This is just a tool to record what's there and to help calculate what should be there. I looked in your profile and did not see an e-mail address. Click on my name, send me an e-mail (not a private message), but be sure to include something about valve adjustment in the subject line so it doesn't get tossed in the spam bucket by my incoming filters.

Once you have all the needed shim sizes figured out, you can determine if any of your existing shims can be re-arranged, to minimize the number of shims you need to purchase. On the other hand, if all your shims are 2.65, you're just plain out of luck as far as the shim shuffle goes. 8-[


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[dardoonk]

Steve, I haven't looked at each shim yet. Three were the same & I was hung up trying to get that dang compression tool to do its thing on the inner cylinders. There's enough pressure on the #2 intake that I cannot even rotate the bucket, when I realized that, I decided to step back and take a breath.

I won't get time on this again until Monday, but I will go down to my local YamaKawaZuki dealer tomorrow and buy a few shims. Hopefully they have some.

[TheCafeKid]

Good luck with that. Maybe your local dealers are better than mine. They ALL had to order, and wanted to charge me around dbl what Z1 would, and i would have to wait for them anyway...

[dardoonk]

I'm not counting on them having any. I stopped today for a set of main jets and they only had two.

I'll probably be visiting Pastor Suzuki next week.. He'll have box full I suspect

[TheCafeKid]

im gonna need more soon too. I dont know what i need yet. I JUST ordered that feeler gauge as i found mine were the same as yours. crap on autozone for not carrying USEFULL gauges..heheheh. Im sure this new 750 motor is tight. I couldnt get the 0015 in there either, but i didnt try em all. One is enough for me to know its gonna need some work. No biggie tho.

[Steve]

If they don't have the Suzuki shims, don't let him talk you into using Kawasaki or Yamaha shims. :shock:

Suzuki shims are 29.5 mm in diameter, Kawasaki and Yamaha shims are only 29.0 mm. Might be the same thickness, but are not as wide.
I don't know about Honda shims, as I have never adjusted a Honda with shims.


.

[TheCafeKid]

actually steve..Kaw shims are also 29.5...HONDA shims and Yammie shims are only 29.0..at least according to Z1....which shouldnt suprise anyone considering where our GS motors are derived.


WAIT...i think i may have goofed...