Valve Adjustments

[jwebfournow]

Hello all
I have a question on adjusting valves on a 1982 GS1100gk, according to clymers, the cam lobes should be perpendicular to the flat surface of the cover of the valve cover edge of the head. Is that correct? specs should be between .03mm-.08mm. I was on Bass Cliffs site and was checking out his valve adjustment for a 1980 850 according to his tutorial the lobes for exhaust are pointed towards front of bike parrallel to the top surface of valve cover head surface I thought the engines were pretty much the same. Another question is the top surface of the valves on the gs1100gk are at an angle, shouldn't the cam lobe be perpendicular to that instead of the valve cover head surface. Also I did a compression test on bike, I get cycl #1 85psi,#2 90psi,#3 85 psi,#4 92 psi valve specs I had a tough time with my gauges, only go down to .04mm and could not get to slide in between lobes to check I'm taking it that they are .03mm or less. I picked this bike up from a friend of mine who got it from the original owner who was a mechanic for a Suzuki dealership. The bike has 20k on it and I don't think the second owner put hardly any miles on it. When I pulled the ignition cover off I can clearly see that there has been a wrench used on the bolt used to turn the motor over, so I'm taking it that the valves might have been adjusted already at some point. How critical is it if the valves are a little tight? I just went and bought a new set of feeler gauges to check it this time. The bike sounds good after rebuilding the carbs but still haven't synched them yet, wanted to do the valves first. Any feedback is welcomed. Also were can I get the gaskets for the ignition cover and valve cover. Other than dealership. Thanks

[BassCliff]

Hi,

The tutorial on my site explains it according to the Suzuki Factory manual procedure. It's the same for your engine. This way, you can measure 2 valves at once. If you point each lobe up before measuring one at a time, you are "loading" another lobe which could throw off the measurements.

When I can't fit my .04mm gauge, I change the shim. If you can spin the shim bucket then there's a little clearance left. If you can't spin the bucket then there is no (or negative) clearance. Valve adjustments are critical. Most of us actually run the clearances on the loose side of spec, perhaps as much as .10mm. "A slappy valve is a happy valve!"

When setting the lobe position for measurement, set the lobes "parallel" and "perpendicular" to the top edge of the head. See the vendor list in your "mega-welcome" for parts (or just click the README link on my website). Keep us informed.


Thank you for your indulgence,

BassCliff

[jwebfournow]

So the Clymer's way is a little misleadin then. If I follow them looks like I have to change all the shims. Does that sound normal to you guys having to change all shims. I'm gonna do it your way and see if I can spin the shim at all.

[BassCliff]

Hi,

You should inventory the shims you have in your bike and make note of the clearances. That way, if you know what shims are installed and what your clearances are, you can "guesstimate" what you'll need on your next adjustment and pre-order a few shims. Mr. Steve has a spreadsheet (send him an email) to help calculate shim sizes and I have a worksheet you can take to the garage to keep notes as you are measuring.

The first time I adjusted the valves on my bike, I had to change 5 shims. It just depends on the wear pattern. Sometimes you can swap shims around in your motor so that even if you do change 4 or 5, you may only have to buy 1 or 2 new ones. ***NEVER turn your motor with shims out!*** You could damage the lobes and buckets.

If all your valves are tight, then you will have to change all the shims. But you might not have to buy 8 new shims if you can move some around to other valves and get the clearances in spec.


Thank you for your indulgence,

BassCliff

[jwebfournow]

Thanks for the info, I can see where I might have to find smaller gauges to make sure of the specs and also find the wrench to compress the springs. Bike sounds good with 20k on it. What did you think of the compression specs?

[BassCliff]

Hi,

Those compression numbers are low. Did you check them with a wide open throttle? Valve adjustment might help, if it's not too late.

CLICK HERE to see what happens when valve clearances are not adjusted. Thanks to Mr. Nessism for the information and pictures.



Thank you for your indulgence,

BassCliff

[jwebfournow]

Just went out and put lobes in proper positions and was able to spin the shim buckets around with no problem. Compression was taken with throttle closed .

[Nessism]

J,

As Cliff noted, the factory method to check the shims is correct since it reduces camshaft deflection from the adjacent valve. Regarding the compression check, the engine should be hot and the throttle held wide open. All these details are well covered in the archives so learning to use the search function will give you these answers much faster than posting a new thread.

[jwebfournow]

Ya I messed up, compression test was done cold.

[SqDancerLynn1]

Those compression #s should come up with the throdle opened even cold....when you check it.. You must adjust the valves and run the engine for at least an hour to get an acurate reading after setting for years

[Steve]

And, when you do a compression test, do two of them. Especially if the first set of numbers seems a bit low.
Do the second test after putting about a tablespoon of oil in the cylinder to seal the rings.
If the readings don't change much, that's GOOD. If they rise, your rings are leaking and the oil is sealing them.

On the valve adjustment, if you look at the "proper" procedures, as outlined in BassCliff's tutorial and any of the service manuals, notice where the cam lobes are in relation to the valves. In the proper position, both lobes on that side of the sprocket are about 45 degrees out of line with their valve. Neither one is pushing on a valve, meaning the cam is not loaded in one direction or another. While the cam is in that position, measure BOTH of those valves. Rotate the crank 180 degrees, you will find the next set of two valves ready to measure. Rotate another 180, etc., you will always find two at a time that are ready to measure.

If you look on BassCliff's site, you will see an addendum with the valve adjustment that is called the "zip-tie method". Try it, it works well. I have the "special tool", too, but have a lot of problems using it. I find the zip-tie method much easier (and cheaper).

Oh, yeah, look at the end of my sig for info on how to get your own copy of my spreadsheet.

.

[BassCliff]

J,
... the factory method to check the shims is correct since it reduces camshaft deflection from the adjacent valve....

I just love that engineer talk!


Thank you for your indulgence,

BassCliff

[jwebfournow]

Hello again!

So lets see if I am getting this. Compression is low when I did a search came up with numbers in the 120 psi to 130 psi, lets say thats preferable. Should do a wet and dry when warmed up. valve adjustment might make a difference there also. My feeler guage only goes down to .04mm when checking my valves I can't get that in there so obviously the specs are smaller I'm guessing in the vicinity of .03mm to ,.02mm when I turn the cam lobes in the proper position to check I can spin the shim buckets with no problems. Without havin the exact size feeler gauge to measure I would be basicaly guessing on a shim to put in there after taking a shim out and seeing what size it is and measuring. I could see what the other shims sizes are that are already in the bike and maybe be able to swap them around for some of the adjustments. So getting the valves in the area of let's say .05-.10mm is going to be the desirable specs. Love the zip tie idea. I saw a video on someone using the tool was slipping all over the area using it. If I wanted to get a feeler gauge that goeas lower any ideas where to get one?

[BassCliff]

Hi,

I think you're getting the hang of this.

A .03mm feeler gauge is so thin that it's likely to break anyway. If my .04mm feeler doesn't fit, I put in the next smaller size shim. I'd rather run the motor with a .09mm clearance than a .03mm clearance.

I would suggest that you go ahead and take out all of your shims one at a time and see what sizes you have. Shims come in sizes ranging from about 2.30mm to 3.00mm with .05mm increments and chances are that you have at least two or three different sizes installed.

If all of your clearances are less than .04mm then all shims should be changed. But you won't know what sizes you need until you know what sizes you have. The sizes are marked on the shim itself, but they are often worn and unreadable. A digital caliper comes in handy for measuring shims.


Thank you for your indulgence,

BassCliff

[jwebfournow]

Okay went out and did an inventory on all the shims, looks like I'll only have to buy a few shims, can switch some around to get what I need into specs of .07mm. that work for you guys? Thanks goes out to all that helped who steeedr me in the right direction. And on a second note the zip tie tool is fantastic, much thanks to Mr. Matchless for coming up with that one.