Valve Clearance Questions

[Guest]

Bought an '83 GS1100G a few weeks ago. The PO last checked the valve clearances 18K miles ago. I checked the gaps per the forum, cylinder 1 exhaust was 0.038mm while all the other gaps were less than 0.038mm...7 out of the 8 gaps are at or below the minimum gap of 0.03mm. Questions: Are the current valve gaps too tight? I checked the current shim sizes using the tie wrap method. Should I replace the shims with shims that are 0.05mm smaller?

[chuck hahn]

Yes..if you cant get the thinnest .03MM in then your dangerously close to being over thight..if the buckets at least spin when the bottom of the cam lone is above them, then youve avoided damage. If they dont...well that should be very telling. I shoot for at least the mid setting of .05MM. .06 or .07 is as loose as I personally will allow.

[tkent02]

That .038mm is still within limits, but the others may not be. The valve clearances generally get tighter with wear, you would be better off to use the smaller shims. Burnt valves suck.

[Nessism]

Sounds like you need to swap all the shims, then check again. Z1 Enterprises sells shims for reasonable prices.

[NashGS83]

Got shims from Z1 yesterday and installed them last night using the zip tie method. Have a question...on Exhaust valve #1, the clearance to start was 0.04mm, removed a 2.60X shim that measured 2.63mm and installed a 2.55X shim that measured 2.58mm and on Exhaust valve #2, the clearance to start was less than 0.04mm, removed a 2.60 shim and installed a 2.55mm shim. Put oil on both sides of the new shims and turned the lobes several times. The new valve clearance measurements were STILL 0.04mm on #1 and less than 0.04mm on #2...how can that be?? Please share your thoughts.

[Nessism]

Got shims from Z1 yesterday and installed them last night using the zip tie method. Have a question...on Exhaust valve #1, the clearance to start was 0.04mm, removed a 2.60X shim that measured 2.63mm and installed a 2.55X shim that measured 2.58mm and on Exhaust valve #2, the clearance to start was less than 0.04mm, removed a 2.60 shim and installed a 2.55mm shim. Put oil on both sides of the new shims and turned the lobes several times. The new valve clearance measurements were STILL 0.04mm on #1 and less than 0.04mm on #2...how can that be?? Please share your thoughts.

This happens sometimes. The clearances are so small that it's hard to get consistent results. I'd run the bike and check them again in a thousand miles or so. You had .04mm before installing thinner shims, so the bike is safe to ride.

[NashGS83]

Thanks for the reply Ed...I'll take your advice. Merry Christmas!

[Nessism]

Oh, and make sure you measaure the valves with the cams in the positions specified by the Suzuki manual. Don't just point the cam lobe away from the bucket since that provides inaccurate values.