GS1000 Valve Shim Clearance Check - HELP!

[GS1000RACER]

Hi fellow GS'ers,

I went to check the adjustment on my 1979 GS1000E's valve clearance today. I checked my Clymer repair manual to get the proper valve clearance numbers. It indicated .0012-.0030 of an inch was within spec. My smallest feeler gauge that I have was .0015. I positioned the cam lobe as directed, perpendicular to the surface of the head, just as the manual directed. The .0015 did not fit under any of the lobes except for one (which was more than .003 clearance). The motor has about 37k miles on it. None of the shims had the thickness showing on them. What should I do? I suppose I should just purchase thinner valve shims, but I thought that generally thicker shims are necessary as the miles go by. Wouldn't the valve clearance get larger as well? I have NO valve shim clearance! Is this correct? I really want to get the valve clearance set up correctly. Also, if anyone knows where I can buy a set of valve shims, please let me know. Please help!

[MrZig]

The valves actually tighten up over use on these bikes.

Also to measure the shims you can use a caliper. Can't really help you out more than that I'm afraid.

[hampshirehog]

As per Mr Zig. I always check with a caliper what's written on the shims as the actual size will be either side slightly.

You're going to have to find your smallest shim and use that to get a measurement on all the valves. Make a note of the thickness of each shim as they come out and the liklihood is that you'll be able to re-shuffle and maybe only buy, or swap with members on here, one or two shims.

[Nessism]

...yes, what the other guys said. Suzuki specifies that the valves are adjusted in pairs, with the cam in specific locations - it's very simple, but not as simple as pointing the lobe straight up on each valve. Check the factory service manual - available for download for free from Basscliff's web site. http://members.dslextreme.com/users/bikecliff/ Also check out his valve adjustment tutorial.

[Steve]

Yep, what everybody has said, so far. It's all true.

In the valve adjustment procedure, you point exhaust #1 straight forward, which puts exhaust #2 straight up, and measure both, ex1 and ex2. Take the points cover off the right end of the crank, use the LARGE nut to rotate the engine (have all the spark plugs out to make it easier) 1/2 turn. Exhaust #4 should be pointing forward now, with #3 pointing straight up, now measure both, ex3 and ex4. Rotate the crank another 1/2 turn, do intakes 1&2, but now intake #1 will be up, #2 will be back.

You mentioned in your original post that your smallest feeler is .0015" and that you also know that the minimum clearance is .0012". If the actual clearance is in that small range, the feeler won't go in, but it might be OK. Changing to the next size thinner shim will put you just over the .003 limit, but that's OK for street use.

In normal use, you won't see the numbers on the shims. You have to remove them and look on the bottom side of the shim. Even then, sometimes the number is worn off or just hard to read, so you need to measure with calipers, preferably digital ones that read in millimeters. To remove the shims for inspection (or changing), you can use the official tool to depress the edge of the bucket and lift out the shim, but many of us have found it easier (and cheaper) to use a folded zip-tie stuck under the edge of an opened valve, then rotate the engine to close the valve. The zip-tie holds the valve open enough to remove the shim.

To help you with the process of recording your valve clearances, shim sizes and determining what you need in there, feel free to send me a request via e-mail (click on my name for address info) and I will send you a copy of my Excel spreadsheet that will help you do that. It is especially helpful since you are measuring in inches and the bike is made using millimeters. The spreadsheet will handle both systems equally well.

Since you are new to all this, I will point out WHY it's better to measure in millimeters, especially when doing a valve adjustment. In inches, the clearance should be 0.0012" to 0.003". In millimeters, the clearance should be 0.03 mm to 0.08 mm. Notice the "3" in both sets? Problem is that one is the minimum, the other is the maximum, and it's far too easy to drop or add a zero when writing things down. It's far easier to stick to metric measurements and minimize the confusion.

And, yes, the clearances on these engines tend to get smaller with use, so don't wait until you hear the valves ticking before you bother to adjust them, it just won't happen. More likely, as the valves tighten up, the bike gets harder and harder to start when cold. And I don't mean 30-degrree cold, I just mean cold as in having set for about 8 hours, no matter the temperature.

Also, you don't necessarily need to buy a complete set of shims. Far better to see what your clearances are, inventory your current shims, see what you can move around (if necessary) and then only buy the two or three shims you need for about $5.25 each. Eventually you will build up a small collection, but buying a set will give you a lot of shims that you will likely never need.

.

[GS1000RACER]

Thank you all for the great advice! I will begin pulling my current shims and see what I actually need in terms of new shims. Also, I will give that folded zip-tie method a try. Does anyone know of a somewhat inexpensive caliper to measure the thickness of each shim? Brand? Type? Steve, thanks for the advice to go to metric. I am normally a die-hard metric man, but the book just showed standard measurements. I will get all the measurements in metric next time. Thanks again!

[bwringer]

Harbor Freight has a digital caliper on sale right now for $16.99 that works great and measures in MM or inches.

Not sure if this was mentioned, but PLEASE don't rotate the engine with ANY of the shims removed. You measure the clearance, remove the shim, measure it or read the measurement if you can, then put it back where it was before moving the engine.

If it's been badly neglected, you may need to go down one, two, or three shim sizes on some of them. I have a thin shim (2.15mm, I think) that I put in when I have zero clearance and can't easily get the clearance in range in a couple of tries. By measuring with the thin shim in place, I can get an idea of where I stand.

Once you've accumulated a decent shim collection, it's dead easy. The hard part is waiting for new shims. Fortunately, Cycle Recycle II is about 20 minutes from my house, so it's pretty easy to run down there for shims. Poke around in your area -- there may be an independent bike shop with GS shims, or maybe a Suzuki dealer that's been around for a while.

[bwringer]

One more point: if you mention where you are or put your location in your profile, there might be a GS-er with a bunch of shims in your neighborhood.

For example, I've shown several people in central and northern Indiana how to check and adjust shims. Once you see how it's done, it's very easy. It's one of those things that's a little hard to get your head around from a printed description. The tutorial on Basscliff's site is excellent.

[Big T]

He's in Canby,OR

Hit Harbor Freight for the caliper and call Beaverton MC about the shims and see if they've got some.

[hampshirehog]

Not sure if this was mentioned, but PLEASE don't rotate the engine with ANY of the shims removed. You measure the clearance, remove the shim, measure it or read the measurement if you can, then put it back where it was before moving the engine.

You can do this if you substitute something in place of the shim. I have a couple of foreign coins (francs or marks, I forget - no other use now 'cos of the Euro) that fit perfectly (well, maybe not perfectly but near enough). Useful when the shims are playing musical chairs.

[twr1776]

bwringer One more point: if you mention where you are or put your location in your profile, there might be a GS-er with a bunch of shims in your neighborhood. For example, I've shown several people in central and northern Indiana how to check and adjust shims. Once you see how it's done, it's very easy. It's one of those things that's a little hard to get your head around from a printed description. The tutorial on Basscliff's site is excellent.

Hey, I resemble that remark. Brian is correct, see if there are any other GSers in your area. Wazz was over last Saturday and with the help of Brians shim kit selection we did his 1000 and my 1000 and then synched both bikes and various other goodies. The shim kit will soon be on way the back to Indy along with the Carbtune/Colortune for the next GS project. I had never done valves before but it actually takes longer to pull the tank & cam cover than to check and change out shims. Who knows maybe if the weather cooperates maybe this weekend it will be smelling kind on "Skunky" in Brown County.