Valve shim measurements

[Tat2demon]

I just checked the clearances on my valves tonight for the first time. Im using go/no-go gauges.

Here are the exhaust valve clearances from left to right - .152, .152, .127, .127

Obviously these are way off of the recommended spec.

Now the big problem. I cant fit my smallest gauge (.102/.152) under ANY of the intake shims.

So my question is, with all of the valves being so far out of whack and the intakes being un-measurable, what should my next step be? Tomorrow Ill pull the cams and get numbers off the shims but with all of them being so far off, should I be looking for other problems?

[crazy steve]

If the bike has fairly even compression and/or was running well, the intakes are probably between .002" and .004". Generally, if the valves get tighter than .002", you'll get a miss or loss of compression. So figure on reducing shim size by two sizes and that will get you very close.

I've seen them too tight to measure, an adjustment will fix it....

[Tat2demon]

Yeah the bike runs fantastic. Hopefully a shop here in town will be willing to do some swapping with me. Would like to avoid buying shims for all 8 valves.

[Tat2demon]

Ok so I just pulled all the shims.

From left to right with the original gaps-

.152 .152 .127 .127
300 295 290 300



NA NA NA NA
270 265 275 275



So...If Im looking at this correctly, what I need is-

295 290 280 290

260 255 265 265


Anyone mind going over the chart and double checking my numbers?

[crazy steve]

Converting those to inches...

Exhaust

.006 .006 .005 .005

I'd drop all of them two sizes; you're better off to hit the upper end of the clearance as that way you'll have longer between adjustments. Each shim change difference is .002", so two sizes will increase them by .004".

That should give you...

EX: .010 .010 .009 .009

IN: .006 .006 .006 .006 (or maybe a bit more; remember, the early intake spec can be as much as .008". A bit more noise, but more time between... )

[GLoweVA]

As far as checking locally, check your BMW bike dealer too. Those Beamers also use the same size shims and they may be willing to trade/sell you shims.

[Tat2demon]

The second place I called had a large box of them. Swapped them out for $3 each.

[Tat2demon]

Got em all put in and everything bolted back together. Retested and two of them are still off by one size. One intake and one exhaust. Steve, your guess of two sizes was right on. Im going to wait until my Motion Pro shows up in a day or two. Im not going to pull the cams for just two shims.

Thanks for all the help guys. Now that Ive done it, not that difficult of a job.