really loose valves

[JTGS850GL]

I'd verify compression. Those clearances are way off for some reason. Them being all on the same cylinder makes it even more suspicious. Bent valves may be a possible cause. How do the cam lobes look? Are there any signs of ware? I've seen poor top end lubrication issues cause excessive cam ware that would cause looseness.

[Charlie G]

If Art doesn't have them, let me know

I'd run a cold compression test and see what you've got

Then proceed to checking the low cylinder, if one exists

Thanks for the offer.

Makes me question, when gaps are that wide, whether I can trust the compression information. Only one way to know. Measure for myself. I'll get it adjusted a bit better and do a compression test. I did buy this bike from the original owner. Doesn't look neglected or abused. Thanks

cg

[Ghostgs1]

Hi Charlie, If you need different shims, we probably have them in the Shim Club stock. Send me an pm if you would like to join the group. Ray

[Charlie G]

Hi Charlie, If you need different shims, we probably have them in the Shim Club stock. Send me an pm if you would like to join the group. Ray

Thanks for the offer. I had forgot about that.

cg

[bikerdave]

smilar question

I just rebuilt the top end on my gs850 new. New rings, honed cylinders, new gaskets. Valves were relapped seals replaced. Problem I'm having is I cant get cylinder 1/2 to fire. All yhe compressions seem very low. Does it take a while to.run the rings in or by grinding tue valves a bit did I raise the valve clearances enough to require smaller shims? I checked the clearances as per the manual. They all seem to have little or no clearance but my feeler only.goes as small as .003 mm. I'm thinking I may have to reduce most or all the shim sizes. Is there a kit I can buy or do I just have to play guess and match?

[Nessism]

I just rebuilt the top end on my gs850 new. New rings, honed cylinders, new gaskets. Valves were relapped seals replaced. Problem I'm having is I cant get cylinder 1/2 to fire. All yhe compressions seem very low. Does it take a while to.run the rings in or by grinding tue valves a bit did I raise the valve clearances enough to require smaller shims? I checked the clearances as per the manual. They all seem to have little or no clearance but my feeler only.goes as small as .003 mm. I'm thinking I may have to reduce most or all the shim sizes. Is there a kit I can buy or do I just have to play guess and match?

You best tend to the valve adjustment. Good thing the engine didn't run because you may have burned the valves if it had.

[Steve]

They all seem to have little or no clearance but my feeler only.goes as small as .003 mm.

I'll bet you just about anything that it doesn't.

The minimum specified clearance is 0.03mm, which is less than one-half the thickness of a piece of paper.

You say that your thinnest shim is ONE TENTH AS THICK?

I'll bet you can see through it.

Please take a good, long look at your feeler gauges. If there are two sets of numbers, one will be INCH, the other will be METRIC.

Part of the confusion is that the minimum clearance in METRIC is 0.003mm, while the maximum clearance in INCHES is close to 0.003". You have that number "3" in both of them, but a different number of zeroes between it and the decimal point. Please look at your gauges again and report back.

.

[Maddevill]

If you ground the valves you no doubt need to re-shim them. The valves will sit lower in their seats with the newly ground faces.

[bikerdave]

Meant to say .003" as in its no where near thin enough. I'm attempting to find a smaller gauge but I can't even slide a piece of paper in on some so.yea I need shims. How do I know which ones or do I just get the next size smaller. I've rebuilt tons of jeep engines. This was my first bike. What a pita its being.

[tkent02]

Meant to say .03" as in its no where near thin enough. I'm attempting to find a smaller gauge but I can't even slide a piece of paper in on some so.yea I need shims. How do I know which ones or do I just get the next size smaller. I've rebuilt tons of jeep engines. This was my first bike. What a pita its being.

I'm sorry, these engines are so much easier to work on than Jeep engines. You just can't use the same Jeep hammers. You are right though, the
jeep's valve clearance adjustments are easier. Back to the GS, Measure the clearance. Use the technique in the Suzuki Service Manual, not Clymers or Haines. If one needs to be changed pull it out and measure it. Get the next size smaller shim, put it in and you are good to go. Have you looked at Steve's spreadsheet?

[bikerdave]

I have the factory service manual but its a bit confusing. As per my statement about jeep engines being easier they are just second nature to me. Older jap Motorcycle engines are new territory for me. The valve shim thing especially. They all seem to be too big. I only lapped the valves a little to reseat them. The major problem was the lower jug gasket was leaking like an old whore. I reringed and honed the cyls and cleaned and resealed the valves while I had it all torn down. I didn't think that little bit would effect it so much. Forgive my ignorance. That's why I'm coming to the pros!

[Steve]

Have you looked at Steve's spreadsheet?

Info is down there.

.