Shim Swap Thread

[greg78gs750]

hey guys, i could really use a 2.50, if anyone has one around, i figure with the shims i have sent out, i can get some good karma? thanks!!

greg

[KRISTI'SGS550]

Hey,
thanks to the members of GS Resources I now have all the shims I need. Thank you again Ray & Greg. Hopefully my next valve adjust I wont need as many shims, but who knows.

Cory

[Ghostgs1]

Lap Master works

A small test has been completed and while it is very slow, it does indeed work. I ran a collection of thicker shims for around 2 hours total polishing time and ended up reducing them by around .04 mm. I think this is going to be a reliable way to get a large supply of shims for not a big investment, at least until I retire. So, if you guys want to try this out and see how it goes, I'll be willing to set up some sort of a group shim pool. I think it would work if each person involved sends in an extra shim that could go into the pool. Let me know what you think.

I talked to a friend of mine who is a metallurgist and he explained that these shims are probably aisi 4140 or similar alloy steel. He indicated that it is a "through hardening steel" so polishing them thinner should not lead to faster wear of the shims. One thing he warned me of was getting them hot and either air cooling them or quenching them in water. He said this type of steel is considered to be "air hardening" and will be come brittle if heated and cooled rapidly. I think he was talking like temperatures where the metal begins to glow red, but maybe not that hot. At any rate this lapping process doesn't produce any real heat, shims aren't even warm to the touch. But, with the concern of possibly cracking shims I wouldn't want any shims sent that have been ground on, just don't want to take any chances.

[Coldeye_]

Guys this thread was the first place I went to when I started shimming my valves, especially after getting a price from Suzuki for shims. Then I went to z1 enterprises. They have shims for 4 bucks and change. I oredered all of mine after they were closed friday afternoon and I just recieved them this morning, monday. I can't say enough about there customer service. Good luck. Still think a shim pool is a good idea!

[Erich Z]

Hey guys, I didn't read my shims close enough when I ordered from Z1, and need two shims of different sizes. I believe I have a 2.55x, 2 2.65, and a 2.45 for trade. I also have a complete O-ring set from our friend Mr. Barr I can't use.

I need a 2.50 and 2.60.

[ChicagoRob]

Shim Swap - Need 255 265 275 285 Have 260 270

Hi All.

Just picked up a '80 GS550L (well, really the boy did) and 6 of the valves are out of adjustment.

I need: 255(3) 265(1) 275(1) 285(1)

I have: 260(2) 260x(1) 270(3)

Oh and I have a question, too. 4 of them were too tight. I kinda expected that. One was just a bit large but one was at 0.20 ! Is this an indication of another problem?

Thanks

Rob

[TheCafeKid]

Hi All.

Just picked up a '80 GS550L (well, really the boy did) and 6 of the valves are out of adjustment.

I need: 255(3) 265(1) 275(1) 285(1)

I have: 260(2) 260x(1) 270(3)

Oh and I have a question, too. 4 of them were too tight. I kinda expected that. One was just a bit large but one was at 0.20 ! Is this an indication of another problem?

Thanks
Rob

Nope. Just that they havent been adjusted in a good while. You COULD run into a burnt valve i suppose, but generally on the exhaust side. The intake side runs quite a bit cooler. How loose was the loose one? Its actually pretty safe to be loose out to .09-.10mm as they tighten with wear and will be beaten into spec in relatively short order. For instance, if i checked my valves, and had one at .04mm, and had the replacement shim size on hand, i would change it. That takes me out to .09mm. Fine by me, while it was already still in spec (.03-.08mm) it just means im not likely going to have to change it the NEXT time im in there. If it were .05, i may be so inclined to go ahead and change it as well.

[ChicagoRob]

Re Shim Swap - Need 255 ...

Nope. Just that they havent been adjusted in a good while. You COULD run into a burnt valve i suppose, but generally on the exhaust side. The intake side runs quite a bit cooler. How loose was the loose one? Its actually pretty safe to be loose out to .09-.10mm as they tighten with wear and will be beaten into spec in relatively short order. For instance, if i checked my valves, and had one at .04mm, and had the replacement shim size on hand, i would change it. That takes me out to .09mm. Fine by me, while it was already still in spec (.03-.08mm) it just means im not likely going to have to change it the NEXT time im in there. If it were .05, i may be so inclined to go ahead and change it as well.

Ok, I'll do what I should have done in the first place and ask advice.

But first, the smallest feeler gauge that I have is 0.04mm, so if the gap is less than .04 I've marked it as <.04.


Cyl Intake/Exhst Gap Shim New Shim
--- ----------- ---- ----- -----
1 Intake <.04 260 255
1 Exhst <.04 270 265
2 Intake <.04 260x 255
2 Exhst 0.20 270 285
3 Intake <.04 260 255
3 Exhst 0.10 270 275
4 Intake 0.50 --- ---
4 Exhst 0.40 --- ---

So you're thinking that I should leave #3 Exhst alone and do both of #4 too?

Thanks in advance for any advice,

Rob
1980 GS550L