Torque spec for 81 GS1100E?

[corpse26]

The Suzuki Service manual states:

Cylinder Head Nut tightening torque: 25.5 - 29.0 lb-ft

But if RapidRay says to use 32 lb-ft, there must be a real good reason for it.

Dropped my cylinder head off to the machine shop yesterday. He's going to mill it the bare minimum so the compression doesn't get jumped up anymore than it is. I installed the 10.25compression wiseco 1168 pistons so I don't want to raise the temperature much more than it will be. I have an oil cooler on the motor but dont know how much it's going to help really.

I tried using the head gasket that came with the 1168 kit thats a cometic spring steel gasket with a crush ring around the cylinders. I don't know where to get a fiber style gasket to fit an 1168?? Anybody know where to get one of these or if they're even made for the 1168?

[chef1366]

APE sells head gaskets for the 1166 kit. So does Schnitz racing.

[rapidray]

I have used the steel shim, the copper, & the fiber gaskets. I still use steel shim & copper. You couldn't give me FREE fiber gaskets & get me to use them. Cometic has all the head gaskets you could ever need. Ray.

[corpse26]

okay....

Okay, well it's been awhile since I've posted up about this issue because it's been the holidays and I've been waiting for some items from the machine shop. It turns out that the oil leak was caused by both the cylinder head and the cylinders being warped. The cylinder head had to be milled .006'' to get all of the warpage out and the cylinders had to be milled .005''.

To counter the space lost by the milling I added an additional base gasket which measures .020'' thick. My valves clear the pistons and everything seems good. However, the bike doesn't start. I set my valve clearance at .003'' and am using 92octane gas.

Is this valve clearance wrong for this bike? (81'GS1100ex)

Could the gas be to high of an octane?

I wouldn't think I'd need to upgrade the ignition coils since this is only the 10.25:1 comp ratio 1168cc wiseco pistons and the additional clearance from the base gasket would drop the compression a little even more.

Thanks for all of the help guys.

[49er]

It's a pity you couldn't get a new .030" base gasket. Your CR would then be closer to 10.5-1. With your present set up, your CR will have dropped below 10-1. The stock CR is 9.5-1.

At .003" valve clearance you are set at the tighter end of the recommended .08 to .013 mm range. The 92 octane gas won't be causing any starting problems unless it's sat for a year or so. Check that you are getting fuel to the carbs and that your choke is working correctly. If these are ok, you may need to re-check the valve timing. Does the engine fire at all? If not, check the spark at the plugs by shorting them against the head while cranking the engine.
Piston to valve clearance has increased by .009" provided the Wiseco head gasket is the same thickness as stock.

[chef1366]

Ian, this is a sixteen valve. The valve clearance is .003-.005 inches.
On the non-starting issue. Is there compression? Is the cam timing out? Is the crank trigger on 180 off? Is there spark? Fuel?

[49er]

Ian, this is a sixteen valve. The valve clearance is .003-.005 inches.
On the non-starting issue. Is there compression? Is the cam timing out? Is the crank trigger on 180 off? Is there spark? Fuel?

Quite right Bill. I realised that it was a 16 valve motor. Suzuki recommend .08 -.13mm (cold). which is .003" -.005". I put a zero incorrectly after the decimal point for the upper measurement in my reply. Great to see you're still paying attention!!

[chef1366]

I should've known that you were using the pathetic system.


Really though I don't quite know why the US hasn't switched. So much easier in tenths. Easier to learn also. We tried to switch when I was in school. I wonder what ever happened to that?

[49er]

Yes, it is the pathetically easy system.
Tens, hundreds, thousands (oops, thous are a confusing point) are much easier to calculate. It used to be a PITA having to convert fractions to metric from drawings, not long after the change to the decimal system here in 1967. Quite easy now with calculators readily at hand on your mobile.

[Big Jay]

Very rare to have a block warped. Same with heads. Most of the time we have to surface a head it is to raise CR or remove a flaw.

Something to think about when surfacing overhead cam heads; These heads have the cam bores line bored parallel with the head surface. If for some reason the head bows from end to end, the cam bores are also bowed.

If the head is reinstalled with big studs and pulled down flat, the cam bores straighten out.

If you take a bowed head and mill the surface flat, the cam bores are now permanently bowed.

Jay

[49er]

Very good point about the alignment of the cam bores. The other thing that happens when you just mill a bowed head flat is the inner chambers end up with greater chamber volume than the outer ones. Best method is to carefully bump straighten the head and then mill out any slight irregularities. Your cam bores will then be closer to their correct alignment too.

[Big Jay]

On rare occasions, we have put the head in a press and took the bow out of it..

[corpse26]

Well, I was able to get the bike started up fine using starting fluid but have been unable to get the bike to run on it's own off the carbs. I stripped the carbs down yesterday to find that the old rubber plugs in the low speed jet tube had pretty much dissolved and clogged both the low speed jet and the main jet. New plugs are on their way. I'm also going to empty out all of the high test gas and put in low test since these coils spark but it doesn't seem to be the brightest spark out there. At least not as bright as the coils on my CBR F2. Which I have an extra set of and was thinking about mocking up on this old GS.

[chef1366]

Make sure you clean the ports from the pilot air and main air jets to the pilot jet and main jet. Blow them out with carb cleaner and air.

[corpse26]

Make sure you clean the ports from the pilot air and main air jets to the pilot jet and main jet. Blow them out with carb cleaner and air.

Any suggestions on were to start out on jetting? It has Emgo pod filters and a slingshot VH exhaust. It was never rejetted when the bike had pod filters and the exhaust put on...thus...why so much stuff was warped and had to be milled.

It had 107' jets in it with the stock carbs. I picked up some 145's...i figure it's best to error on the rich side at first. Anybody have a similar set up with stock carbs and an 1168 kit in it?