valve adjustment

[Counter]

Just got into my '80 850 today. Four of the valves had clearances less than .038 mm. As that's the smallest blade I have, I had to approximate. I have dropped 3 of the 4 a full .1 mm. I am waiting on the last one from the local Suzuki dealer as their shim assortment wasn't as full as it should be.

Even after adjusting them, only two of the valves are between .06 and .089. The rest of them are all between .038 and .051 mm. Except for the one on which I a waiting for the shim, of course.

I don't have any idea how long it has been since the valves were last adjusted. Also, one of the little beggars was put in with the lettering up and not down. It took me about 15 minutes to decide it was 2.75. Either I need new eyes or a better magnifying glass.

I know that everyone on this board seems to think that the valves should be as close to .08 as possible. Am I OK with these gaps?

Also, since I now have a 2.75 (I think), and a couple of 2.65's, how do I join the shim swapping club? My dealer charged $5 and change for each shim. While I don't think it is outrageous, the lower the cost the better.

 

[TheCafeKid]

If they're within spec, ride the sucker. You'll eventually have to change the ones that are closer than others, but in the meantime, I wouldnt bother. You see each shim size is going to add .05 to whatever your current clearance is. For example, Your current shim is a 2.75, with a clearance of .04mm. The next smallest shim is a 2.70. Your clearance will now be .09mm While its OVER spec, its not going to hurt anything. A member of this board, havent seen him in a while (Kurt, wtf are you??) had an old road racing mentor he consulted with all the time while rebuilding/refurbing his GSs.. Pastor Suzuki he called him. Anyway this Pastor Suzuki said that when he was still building race bikes, they'd run the clearances out to .12-ish without worry of spinning a shim out of the bucket. Would I do it? Probably not, but I wouldnt worry about a clearance as far as .10. That is to say, when I do a valve adjustment, if .05 feeler doesnt fit, Im changing the shim to the next smaller size... But I could leave it alone too and be just fine..

 

[Nessism]

If you do a search on "shim club" you can hook up with Ghostgs1 who manages the exchange program. Z1 Enterprises sells shims too for $5 each so it never hurts to stock up.

 

[Counter]

OK, another follow up question.

When I checked the valves, sometimes the lobe wasn't exactly as shown in the drawings. The lobe itself wasn't touching the shim (I could move the ring and shim). A couple of the valves were > .038 after testing, but were under .038 mm right before I put the cam cover on.

I know that in both circumstances the lobe was pointed away from the shim. Isn't the cam perfectly concentric around the cam spin axis except for the cam lobe and ramps? Shouldn't the gap between the cam and shim remain constant as long as the lobe or ramp isn't pointed toward the shim?

I think the bike runs better than before I adjusted the shims. I have a leaky head gasket (again) and will probably have to take the head off and replace the gasket soon, so I want to make sure the valves are properly adjusted. I also have a leaky cam cover (with a new Athena gasket). I just snugged the bolts enough to secure the cover, so I don't think I over tightened the bolts.

This was my first attempt at the valve shim adjustment.

 

[Steve]

If you position the cams correctly, according to the pictures, you will be able to check the clearance for two valves without moving the cam.

The procedure is rather simple, but does not come across that way in print. Align the cam lobe on EX 1 so it points FORWARD and the lobe for EX 2 is UP. Note that in this position, both lobes are abour 45 degrees off-axis for their respective valves. Measure the clearance on both valves.

Rotate the crank 180 degrees. This will have the the intake valves for 1&2 lined up properly. Check both of them.

Rotate the crank another 180 degrees, the exhausts for 3&4 will be lined up.

Rotate the crank a final 180 degrees, the intakes for 3&4 will be lined up.

Can't get much easier than that, ...

... unless you need a way to record all your findings.
Follow the suggestion in the last part of my sig.

.

 

[BassCliff]

Hi Mr. Counter,

Yes, Mr. Steve's spreadsheet is very handy for keeping track of your shims and clearances. Then you can "guess-timate" what you might need for your next adjustment and order a few ahead of time. For my 850, I also use the Real Gaskets silicone reusable valve cover and breather gaskets. That way you don't have to wait for any parts, gaskets or shims, when it comes time to check your valve clearances. Everything should be pretty well documented in the valve adjustments guide on my website.

Keep up the good work!


Thank you for your indulgence,

BassCliff