Valve adjustment questions

[WilliamGLX81]

I would just pull the plugs.

The plugs have been pulled since I removed the valve cover. It's necessary for the "ziptie method".

[Steve]

I was thinking about running the starter, but I think I should put the valve cover back on at least loosely. Right?

I don't.

.

[WilliamGLX81]

Well, then. I'll see if the cam chain gives me a skunkstripe. Heh.

[WilliamGLX81]

Hokay, spun the engine (valve cover off) with no bad results. Most of the readings shaped up, except two troublemakers.

Now I've got these clearances:
1 2 3 4
In .06 .06 .10 .06
Exh <.04 .05 .07 .07

The <.04 was with a 2.55x shim, which I measured to be 2.60/2.61... Seems odd. The .04 feeler measured as .04 with the same pressure on the caliper wheel.
The .10 is what I wound up with once I moved that 2.55x shim to Intake #3. I've got 2x2.65x and a 2.65 shim. I think I crammed a 2.65x shim into Exh1, but I forget what size it was now. I'll have to measure it in the morning.

name measured
2.65x 2.70
2.65x 2.70
2.65 2.68

The .10 is ... ok I guess. But kind of far off from the others. I guess it's fine.

So for Exhaust #1 I'll need to get ahold of a 2.55 shim, since the 2.55x is too big.

[WilliamGLX81]

Anybody else have shims that measure larger than the size marked on them?

And make that a 2.50 shim for exhaust #1. I'd rather the clearance be a little big than a little small. As in .10 would be preferable to .05.

[Nessism]

You need a micrometer to properly measure shims, not calipers. And yes, it's common to find shims that are in between sizes. The larger in between sized ones received that X designation. When adjusting valves it's useful to have a micrometer to measure your spare shims, assuming you have spare shims, so you can look for just the right size. At least that's what I do anyway.

[WilliamGLX81]

Everybody recommended calipers. I would have gone micrometer if I had the extra $20 to spend on one.

These shims that are bigger than their marking do not have the x designation. The standard are reading .02-.04mm larger than they should, and so are the x designated shims.

[tom203]

micrometers are more accurate- a caliper's narrow contact point causes problems plus you have to be consistent with hand pressure. I found very few shims marked correctly ( i have an accurate mic used for years on tight tolerance work). But either tool will give you a decent relative idea of one shim to another. Don't obsess about getting the exact size shim- I run all mine to high side or just over.

[koolaid_kid]

While a mic is better calipers will get you in the ballpark. Bottom line is you need to install a shim and then measure the clearance. I also have never met a shim that actually matched its markings.
Just be glad you have shim over buckets. I have shim under bucket on my GPz, which means I have to remove the cams to change shims. PITA, but they won't spit out at 11000 rpm.

[WilliamGLX81]

While a mic is better calipers will get you in the ballpark. Bottom line is you need to install a shim and then measure the clearance. I also have never met a shim that actually matched its markings.
Just be glad you have shim over buckets. I have shim under bucket on my GPz, which means I have to remove the cams to change shims. PITA, but they won't spit out at 11000 rpm.

Actually, it seemed like it might be less work to remove the cams than to spin the motor and do each shim one at a time. Except then you can't re-measure without a lot of trouble. 11,000 rpm eh? I haven't gotten my bike over 6 grand yet (leaky carb boots and valves out of spec). What kind of bike? A GPz?

[tkent02]

Any of these GSes will do 11,000 just fine, especially the smaller ones.
Never had a shim come out.

[koolaid_kid]

I wouldn't know, I never had a shim-based GS.
My GPz is still pulling at 11k, but the rev limiter kicks in and I am done. Hit it while I was chasing down bwringer on his GS 850 and it surprised me a bit. The rotating assembly is balanced and I have read they can approach 15k, but my GPz 900 ignitor has a built-in rev limiter.

[WilliamGLX81]

Daaang. That's amazing. Rev limiters... well. they suck, but they can also save your bacon.

I've gotten a 2.50 shim locally, and I've now got a .013 clearance. Is that too big? Only one other is nearly that size, and it's .011.

[koolaid_kid]

You need to send an email to Steve and get a copy of his valve adjustment sheet. It is used during valve adjustments to record current clearances and shim sizes, new clearances and shim sizes, and is really handy for figuring out what shim needs to go in next. Just get a copy from him, print out several copies and use them, and now you will have a record you can use when you go to check clearances the next time.

[WilliamGLX81]

I've got it, and got it filled out. It was helpful to do them en masse. I got 3 shims from him, swapped some others around, and just wondered if .013 is too far over the spec. Some people mentioned running at .010, so I wonder.