Shims for valve ajustment

[Steve]

I dont understand what that means. I was under the impression that I would need to change them as needed or when the gas closes.

That was a response to Chuck Hahn, who was suggesting grinding them to custom thicknesses.

Yes, you will need to change shims occasionally.

Have you opened up your engine yet to measure clearances and inventory your shims?

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[jon]

No I haven't. I am planning to ride the rest of the season then do the job . Possibly have the whole motor gone threw. I was just hoping there was a kit or a certain number of shims I could purchase that would cover most cases. Also I did try my local dealer and they dont have any. In fact they brought out 4 boxes of very small in diameter shims like 7.3 or something and when I questioned the sizes said shims are shims. After a a quick conversation we came to agree that they just didn't have what I needed.

[jon]

Also is hitting quick reply the best way to reply to specific people ,as in these replys?

[Rich82GS750TZ]

Also is hitting quick reply the best way to reply to specific people ,as in these replys?

Quick Reply keeps the conversation going, but if you want to be specific about whom you are addressing, it sometimes help to use the Reply with quote on the bottom of the post you want to respond to. That's what I did here.

[Steve]

Also is hitting quick reply the best way to reply to specific people ,as in these replys?

Hitting the "Reply" button is pretty much the only way to respond. However, if the thread is really busy, with many different posters, you might want to go back to the post you are replying to and hit the "Reply With Quote" button. That will copy their post, then you can enter your reply. NOTE: if the quoted post is very long, possibly with several other points, you can edit out the irrelevant stuff and leave just the point to which you are replying.

Back to your valve shims: go back and re-read the replies in posts 2, 3, 4 and 5. There were no "standard" shims in the engine when it left the factory. Due to production tolerances, there were variations in the clearances, which required different shim thicknesses. It was common to find shims in the 2.65 to 2.80 range, but there is also no way to know if they have been changed since new. As an engine wears, the required shim thickness will decrease, but until you open up your engine, measure your clearance, then remove the shim to see its size, you will have no way to know what shim needs to be in there.

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[Brendan W]

Bear in mind that when Steve says take inventory of your shims do not rely on the thickness on the shim. It may have been ground before. You might spot tell tale marks depending of how good or bad the grinder did the job. It's good practice to verify with a vernier caliper.

[Steve]

True enough, but hopefully, if the person that did the grinding was concientious enough to grind on the side with the printed numbers, you would HAVE to measure the shim to know the thickness.

Fortunately, not many people have access to proper grinding machines, so this is a rather rare situation.

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[chuck hahn]

I measure every one regardless. That may be just me. I wipe them real dry before measuring too...oil adds thickness

[Brendan W]

I measure every one regardless. That may be just me. I wipe them real dry before measuring too...oil adds thickness

I should hope so otherwise we're wasting our time filling sumps
Seriously, it's no harm to get a reminder of what oil is expected to do.

[salty_monk]

GhostGS ground me some down to custom sizes to put them all on top tolerances in the skunk many moons ago...

[Brendan W]

About five of mine are at or close to the thinnest stock shim. Is there a red line for thickness and you go to the valves?

[Steve]

If you have that many that are approaching the minimum, you might want to step back and evaluate the rest of the engine.

The way to fix that would be to remove 0.5 to 0.7mm from the tip of the valve. That would require shims that much thicker.

While you have the head off to remove the valves for their shave job, you should also install new seals.

How are the rings? Any other gaskets leaking that would be easier to change while the engine is apart?

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[Brendan W]

The engine is tired. The 53k on the odo is optimistic I'd say judging by the state of the cam chain runners. I did a top end gasket and seal job in 2014 with a ?70 complete engine set. I was losing a liter per 400 miles at the time through the front of the headgasket. Bores were good. I have engine oil leaking into the intermediate transmission space as well. Cosmetically the bike is not the best and an unlikely candidate for a full restore.Seat pan is cracked headers getting rusty. It keeps soldiering on. It's been down hard on the right. There is a brake pedal gouge in the clutch case and it has a round master for the front brake and the turn signals are the later plastic type and the engine mount plates are stainless steel. Bit of a Frankenbike and probably going for parts if or when I ever replace it. Still starts on the button and with two up it just pours on the torque in top gear at silly low speeds.

[Chuck78]

About five of mine are at or close to the thinnest stock shim. Is there a red line for thickness and you go to the valves?

Time for a machine shop valve job and evaluation of the valve faces. When they are worn that much that you are at the thinnest shims, the valve faces are very worn and eroded, and your head will be flowing in a sub par manner.

[Brendan W]

Time for a machine shop valve job and evaluation of the valve faces. When they are worn that much that you are at the thinnest shims, the valve faces are very worn and eroded, and your head will be flowing in a sub par manner.

Seems like some one tried to do a lot with the motor. When the head was off the valves seats seemed too clean like a recent job. Maybe they went too deep or had to.