camshaft installation

[brutaldm]

bike: 1982 gs650gl 30k miles
location: western mass


I have a gs650. the bike is in crap condition and i'm bringing it back to life mechanically. (forget the cosmetics)

I'm trying to put the camshafts back in. Lining up the TDC mark is a no-brainer and I got that part done. The #1 and line (on the sprocket) are both pointing towards the FRONT of the bike and parallel with the gasket. The part I'm having a problem with is getting the exhaust camshaft to stay put while I torque down the journal covers. As I torque down the covers, the pressure of the valve spring causes the camshaft to rotate and throw off the alignment by a tooth or two.

What's the trick to torqueing down the journal covers while keeping the camshaft aligned AND the TDC mark aligned?

 

[doctorgonzo]

Per the manual, you use a large set of vise grips to lock the cam down to the head. I don't have the photo handy, but there is a spot where one jaw will fit a recess in the head, and the other on top of the cam. Squezze it down and it will depress the valve and lock it in place while you install the journal covers.

 

[Theo]

I just did this recently. In my clymer manual it says to take up all of the slack in the cam chain on the exhaust side, then put the camshaft in. Now if you keep the chain taught, it should keep the camshaft from rotating while you tighten it down. It's very akward but it worked for me. I hope that helps.
-Theo

 

[doctorgonzo]

Again, unless this bike is different that most of the them. The official Suzuki service manual says to clamp the cam down with vise grips to lock it in place so it won't move, and so you have the journal cap flat and level as you tighten it down not cockeyed from the cam being at an angle.

 

[brutaldm]

Again, unless this bike is different that most of the them. The official Suzuki service manual says to clamp the cam down with vise grips to lock it in place so it won't move, and so you have the journal cap flat and level as you tighten it down not cockeyed from the cam being at an angle.

hmmm i have both the clymer and suzuki service manual. Neither of them mentioned using vise grips. What part of the cam do you grip with the vise grips?

 

[Guest]

I've never used vice grips.
I put in the intake cam and count the links to #3 but don't but on the cam caps yet. Hold the chain tight with the intake cam and put on the cam caps on the exhaust cam.
Before putting on the intake cam caps release the cam chain tensioner while holding the cam chain tight with the intake cam. Doing it in this order keeps the cam chain from binding.
Now put on the intake cam caps.
DO NOT over tighten.

 

[doctorgonzo]

650 MAY differ.

I didn't find installation procedure, but the disassembly procedure (for the GS1000) says "Grip the camshaft with vice (nice Japanese spelling) pliers, then loosen the 4 bolts...". I shows a picture of the pliers clamped to the head holding the shaft in position. Assembly is the reverse.

Anywhere that's not the lobe or the journal. There is a rough ditch on the cam between them.

 

[doctorgonzo]

"DO NOT over tighten."


And the congregation said amen.

 

[posplayr]

"DO NOT over tighten."


And the congregation said amen.

wasnt there a recent thread about torque readings? ^o

 

[doctorgonzo]

wasnt there a recent thread about torque readings? ^o

In my budget is a torque wrench that will read that low. I have a nice 10 to 100, but 6.7 (cam covers). I do by "feel". I've only ever broken one, and that was early on over a year ago.

 

[gearhead13]

"DO NOT over tighten."


And the congregation said amen.

Ya, those little bolts will strip out faster than you can say "helicoil"
I have never done a 2 valve, but with mine i just torque down the intake cam, as long as the chain doesn't skip a tooth its fine, then tighten the chain tensioner until the slack is gone.