Tappet tool source

[tkent02]

GS750GUY here again. The guy that started this thread.
Thank you, thank you, thank you!!!! After 30 minutes in the garage I'm back to tell you I'm a confirmed ZIP TIE believer. It worked slicker than a whistle. I removed & put back each shim, logged the thickness and am back here in 30 minutes to tell you about it. No problems what so ever! For the guys that experienced breakage of the tie; I can't imagine what caused it. The ties I used showed little if any wear at all.
A while back I requested the email for the the shim conversion chart but for some reason am unable to open it.
Below is the readings I got from my 8 valve 78 GS750EC. According to my manual the valve gap is to run between .03 & .08 MM. The following is my list of readings. I have numbered the valve starting with valve #1 which faces the front of the bike.
Can one of my fellow GS'rs out there with a conversion chart tell me what I need to do based on the information below?
Thanks a million for everyones help with this thread!!
GS750GUY
I can't wait to ride!!!!!

INITIAL VALVE CLEARANCE MEASUREMENTS

#1 #3 #5 #7
.08MM .08MM .08MM .08MM

#2 #4 #6 #8
.09MM .11MM .11MM .08MM

SHIM THICKNESSES

#1 #3 #5 #7
2.70 2.75 2.75 2.75

#2 #4 #6 #8
2.75 2.65 2.70 2.65

Leave 1, 3, 5, 7 and 8 alone.
Make 2, 4 and 6 one size bigger. Buy a 2.80 for #2, put the old 2.75 from #2 into #6 and put the old 2.70 from #6 into #4.

 

[GS750GUY]

Leave 1, 3, 5, 7 and 8 alone.
Make 2, 4 and 6 one size bigger. Buy a 2.80 for #2, put the old 2.75 from #2 into #6 and put the old 2.70 from #6 into #4.

Thanks tkent02!
If I leave 1, 3, 5, 7 & 8 alone won't I just be replacing them soon since they are all on the far outside of my gap range? Should'nt I install thicker shims and get the gap back down to the .03 end of the range so I can extend the time I will have to replace them?
GS750GUY

 

[Greg O.]

I used the zip tie method, and was a very happy customer for spending $.05. It was very easy, and no broken or even squashed zip tie. Just do one valve at a time, after you have checked the clearance. I found a good pair a tweezers makes it easier to remove the shim.

Greg

 

[tkent02]

Thanks tkent02!
If I leave 1, 3, 5, 7 & 8 alone won't I just be replacing them soon since they are all on the far outside of my gap range? Should'nt I install thicker shims and get the gap back down to the .03 end of the range so I can extend the time I will have to replace them?
GS750GUY

Actually it goes the other way, usually the clearance decreases with wear as the valves recede into the seats, the whole assembly becomes longer and thinner and thinner shims are required as the engine ages. It is normal to see several at the tight end of the tolerance, around .03mm. Yours is kind of unusual to have so many at the loose end.

Who maintained it last?
Mostly POs don't have a clue and do strange things in there.

 

[GS750GUY]

I agree that the zip tie works great and I had no problem. I would not use thin little cheap ones if you're worried about breakage.

As far as your measurements I wouldn't bother changing any but #4 and #6 may be slightly over spec. A 2.70 in #4 would bring you down to .06mm and a 2.75 in #6 would bring you down to .06mm if they are correctly marked. A 2.65X and 2.70X may dial you in to around .08mm. If you haven't done so I would check your measurements a second time just to verify.

I guess I must be misunderstanding the whole purpose or the process. If I understand my manual corectly concerning the procedure it reads like my goal is to replace all necessary shims with thicker ones to get my feeler guage gap back down to the .03 end of the gap range between the cam lobe and shim. If most of my shims are still within spec at but at the .08 far end of the allowable gap range won't I need to replace them anyway in a year when they finally hit .09 and out of the spec range? Since I already heve the valve cover off why not replace them all and take the gap back down to or as near as possible .03 MM? Then I won't have to concern myself with them for several years.
GS750Guy

 

[Dogma]

I guess I must be misunderstanding the whole purpose or the process. If I understand my manual corectly concerning the procedure it reads like my goal is to replace all necessary shims with thicker ones to get my feeler guage gap back down to the .03 end of the gap range between the cam lobe and shim. If most of my shims are still within spec at but at the .08 far end of the allowable gap range won't I need to replace them anyway in a year when they finally hit .09 and out of the spec range? Since I already heve the valve cover off why not replace them all and take the gap back down to or as near as possible .03 MM? Then I won't have to concern myself with them for several years.
GS750Guy

One of the other guys pointed out that the gap usually gets less over time, not more. So, the gaps will all gets smaller until there is not clearance, at which point the valves don't close completely and start getting burnt. I'm not sure exactly what it is that wears, but it's not the cam or shims.

As an example of how easy it is to miss posts in these long threads, I completely missed your question about how not to turn the engine over with no shims in it. What you have to do is check each shim, then put it back in before moving on to the next. Most shims won't need to be changed, so you put them pack in and be done with them. The ones that do need changed you have to put back in until you have the replacement. The reason you shouldn't turn the engine over without the shims is that you will damage the corners of the cam lobes. A normal cam lobe has nice square edges. One of mine now looks like it was attacked with a chisel, and I had to fish the little broken bits of metal out with a magnet.