Valve adjustment info...

[tkent02]

Trying to adjust the valves on my new GS. My new Suzuki manual is apparently stuck in the mail someplace. I could use a little info. I found all this by searching on the GSResources.

This for a 1980 GS 750E, TSCC

start with this:

Here's how you want the cams positioned for adjusting. With the crankshaft at the T mark on the signal generator and the notches in the cams facing away from each other you adjust the intake and exhaust valves on #1, EX on #2, and IN on #3. Then rotate the crank to the T mark with the notches in the cams facing each other. You'll adjust IN on #2, EX on #3, and IN and EX on #4.

So far, so good.

I have seen two sets of specs, one says all about .005 - .006 inches

Or

Intake 0.025-0.052 mm
0.0010-0.0020 in

Exhaust 0.040-0.067 mm
0.0016-0.0026 in

Mine are all .003 - .005 inches, I don't want to go tighter until I have the correct spec.

Can anyone please email me the manual page that covers valve adjustments?
Or steer me towards an online shop manual that I can get into myself?
I found one for my '78 GS750, but not for the '80.

Or at least confirm the correct clearances for me?

Thanks very much for any help.

[Tarbash 27]

My clymer manual says for 1980-1982 GS750 TSCC (4 valve)

For all valves
0.09-0.13 mm (0.004-0.005 in.)

[UncleMike]

My clymer manual says for 1980-1982 GS750 TSCC (4 valve)

For all valves
0.09-0.13 mm (0.004-0.005 in.)

That's correct.

[Steve]

I can't help you with exact numbers for your bike, but there is a general principle to be followed. Adjust them LOOSE.

Most of the shims I have seen are about .002" different in thickness. If you are measuring .004", consider changing the shim so you have .006" clearance. You will not get any more noise, and, unless you are racing on a closed course (where you need EVERY last bit of power available), you will have better usable power with looser valves. The intake valve will close just a bit earlier with loose valves, preventing the mixture from being blown back up the intake tract. At higher engine speeds, inertia takes care of that, but at more casual road speeds, a looser valve helps a bit. I do know that the listed clearance for my 650 and my 850 is only .001 to .003", so I can't afford to ever let them get tight. If they tighten up much from those specs, they won't be closed.

You might lose one or two horsepower at the peak, but you will probably gain a pound or two of torque below the peak, where we do most of our riding.


.

[tkent02]

Thanks, guys!!

Tarbash and Mike, thanks for taking the time to look up the numbers. Steve, yes I always go on the loose end of the specs, mostly because too tight causes problems.
Thanks for the help!

[t3rmin]

Here's something to keep in mind when obtaining new shims: if they're marked with an "x" after the number, they're slightly thicker (or was it thinner??) than specified. That threw me off for a while. In the end I relied on my digital caliper to give me exact thicknesses, rather than the markings.

[UncleMike]

Here's something to keep in mind when obtaining new shims: if they're marked with an "x" after the number, they're slightly thicker (or was it thinner??) than specified. That threw me off for a while. In the end I relied on my digital caliper to give me exact thicknesses, rather than the markings.

Good info, but don't listen to him. You don't have shims.

[Billy Ricks]

Good info, but don't listen to him. You don't have shims.

You're learning quickly Mike, threaded adjusters on the rockers.

[UncleMike]

You're learning quickly Mike, threaded adjusters on the rockers.

Sooner or later I get something right,...*

[t3rmin]

Good info, but don't listen to him. You don't have shims.

Erp.

Well, you know, I was just sayin' that in case he ever *did* have a motor with shims. Yeah.

[tkent02]

But I DO have a shim motor...

Erp.

Well, you know, I was just sayin' that in case he ever *did* have a motor with shims. Yeah.

Going to adjust the valves on that one next.
So now I'm way ahead of the game.

[UncleMike]

Going to adjust the valves on that one next.
So now I'm way ahead of the game.

See? Everyone's a winner!

[t3rmin]

See? Everyone's a winner!

Reminds me of old Mister Barnslow getting out every morning and nailing a fresh load of tadpoles to the old board of his. Then he'd spin it round and round, like a wheel of fortune, and no matter where it stopped he'd yell out, "Tadpoles! Tadpoles is a winner!" We all thought he was crazy. But then we had some growing up to do.

[UncleMike]

Reminds me of old Mister Barnslow getting out every morning and nailing a fresh load of tadpoles to the old board of his. Then he'd spin it round and round, like a wheel of fortune, and no matter where it stopped he'd yell out, "Tadpoles! Tadpoles is a winner!" We all thought he was crazy. But then we had some growing up to do.

Those are some deep thoughts.

[Billy Ricks]

Those are some deep thoughts.

Sounds like some of the things we used to do with hardheads, that's a saltwater cat here for those not familiar. Back in the mid '80s we spent about 4 months on one job near S. Padre Island. Out of boredom we used to do some crazy schitt to hardheads. I won't post those things here, but it was out there.