1980 GS750LX TSCC valve adjustment?

[basic]

Hello all.

After reading many many posts it seems that the common consensus is to adjust your valves to help promote a happy running motor. While I've not even started my engine yet (cleaned carbs + new o-rings, new to me tank, new petcock, fuel lines, etc) I figure that I should do this as well. After reading the article how to on basscliff's site, i understand (mostly) how to do it, but it says that the 16v engines don't use shims. If this is the case, how do we 16v guys adjust clearances? Does anyone have or has anyone seen a right up like on b-cliff's site? I also don't have ANY manuals for this bike, so if anyone has any good downloads for help, that would be awesome. Thanks.

[Steve]

I don't know of any pictorials posted on the forum yet, so take LOTS of pictures and send them to Cliff so he can post them. :shock:

I have not yet had the pleasure of checking the valves on a 16-v engine, but the process of checking them is pretty much the same. You will have to find the proper clearances, as I think they are different than the 8-v clearances, but check each valve for clearance numbers. If adjustments are needed, there are threaded adjusters and locknuts for each valve. It might be a bit tricky to get each pair of valves with the same clearance, but I am not sure.

Let us know how it goes.

.

[tkent02]

I don't know of any pictorials posted on the forum yet, so take LOTS of pictures and send them to Cliff so he can post them. :shock:

I have not yet had the pleasure of checking the valves on a 16-v engine, but the process of checking them is pretty much the same. You will have to find the proper clearances, as I think they are different than the 8-v clearances, but check each valve for clearance numbers. If adjustments are needed, there are threaded adjusters and locknuts for each valve. It might be a bit tricky to get each pair of valves with the same clearance, but I am not sure.

Let us know how it goes.

.

Works well to have two feeler gauges, one for each valve of the pair. Get them both feeling the same drag at the same time as you tighten the locknut. Not too tight on the locknut. It helps to have four extra fingers on your left hand.
Make a pair of tools out of wood screws with the 1/8 square head, like an allen screw but the hole is square. This fits the adjuster which is a square headed screw. I used a wooden dowel for a handle, thread the screw in a little bit and that's your tool.
Quicker and easier to adjust than the earlier shim setup, doesn't last as long and requires adjustment more often.
Basic stuff, post up your pics for basscliff.

[basic]

any word on the tolerances? also i'm assuming it's the same procedure as the 8v, but with twice as many valves.

[tkent02]

any word on the tolerances? also i'm assuming it's the same procedure as the 8v, but with twice as many valves.

Not the same at all, no shims.
Take your valve cover off and look, you will know.

[basic]

well yea, the same as in the direction to point the lobes. without the shims i also don't need the tool to remove the shims, which seems like it may be easier, but then i have twice as many to do as well.

[rphillips]

.003" to .005" for both in. & ex. Not necessary, but very handy, is the little adjusting tool that turns the adjuster & holds it while tightening the lock nut. I think appx. $10

[basic]

.003" to .005" for both in. & ex. Not necessary, but very handy, is the little adjusting tool that turns the adjuster & holds it while tightening the lock nut. I think appx. $10

thank you rphillips very much for the tolerances...those are in inches correct? Not in MM? just seems like .08 to .13mm is a big space. I'll try and get the cover pulled on thursday and get them adjusted. Hopefully I can re-use the gasket, if not i will order another. And I'll take lots and lots of pictures. Thanks to tkent02 with the idea for the tool to adjust. I'm sure it will help tons.

[basic]

ok, pulled the cover off tonight and looked around under it. If I were to guess i'm supposed to check the clearance between the adjustment screw and the top of the valve. Only question I have is what direction does the cam lobe for a specific valve need to point? should it be directly away from the rocker arm or should it be parrell with the head? Thanks for all the help guys. I'm making sure to take some pics.

[Nessism]

Basic,
Get yourself a manual. I think repairmanualclub.com has a free download for your bike (might be listed as GSX750, not to be confused with GSXR). At any rate, you need to figure out the proper cam positions; pointing the lobe away from the follower is not good enough since the adjacent cam lobe will skew the cam in the journal clearance if the cam is not in the proper position.

Good luck.

[basic]

are the valve clearances on the 16v engine checked with the respective piston at TDC? I just read a general How-to and it said clearences are checked with the valve's piston at TDC. I've got a clymers manual on order for it, but it will be a few days before its in.

[psyguy]

this is a procedure for 8v
see if it helps

Exhaust valves (front)
Rotate the crankshaft so the outer cylinder's (#1) cam lobe is pointing FORWARD, the inner lobe (#2) will be pointing UP. Check the clearance of both valves.
Then rotate the crank 180 degrees so the outer cylinder on the other side of the engine (#4) is pointing FORWARD and the inner one (#3) is pointing UP. Again, check the clearance of both valves.
Intake valves (back)
Rotate the crankshaft so the outer cylinder's (#1) cam lobe is pointing UP, the inner lobe (#2) will be pointing BACK. Check the clearance of both valves.
Then rotate the crank 180 degrees so the outer cylinder on the other side of the engine (#4) is pointing UP and the inner one (#3) is pointing BACK. Again, check the clearance of both valves.

The idea is that both valves measured by this method are untensioned which makes the clearance measurement more consistent than if the cam lobe next to the measured valve is being depressed.

[chef1366]

Take off the valve cover and with a .005 inch feeler guage, 9mm wrench and a small pair of pliers. Once you get in there it's really cut and dry. It's not hard or scary. Make sure the cam lobe is directly opposite the rocker when adjusting.

[Pete Logan]

I think repairmanualclub.com has a free download for your bike (might be listed as GSX750, not to be confused with GSXR).

They have one listed as GS750 Service Manual which I'm downloading now. 86 megs .pdf file.

I'll check what it covers and post back when it's done.

They list GSXR750 separately.

Edit: The site limits free downloads to 3 files and 100 megs a month, so you should be able to get 1 manual anyway. Over this, it's $3 a month for 9 files and 900n megs a month. This still looks cheaper than buying them, even including print costs, but we'll see what the manual actually is.

Second Edit: This manual is for the 8-valve only. It does not cover the TSCC motor.

There is a listing a little further down for the GSX750 (the European designation) at 18 megs, but I'm out of free download, so that's all I can research for another month - anyone ?

Third Edit: On Page 4 of the listings there is a service manual for GSX750E and GSX750ES 1983, which has to be a TSCC book, but it's 146 megs, so outside the free download limits.

I'm stuck :-D

[rphillips]

There should be a square notch, cut in the end of each cams. With the in. notch & the ex. notch pointing straight towards each other, gasket surface centered in notch, adjust 1/2 of the valves, rotate the crankshaft till the notches are opposite of each other, gasket surface centered in notch, adjust the others. This is for the 1100 TSCC