Zero compression XS1100

[prometheus578]

"The ankle-bone's connected to the shim-bone..."

I have nothing to add... Just don't like seeing T.C. get in all the good quips! (or the bad ones, either)

[mn2346]

Just a comment to make sure...

It is NOT neccessary to remove the camchain while adjusting the shims. There is a special tool that will allow the swap without removing anything else besides the oilcover.

Who has the picture of the tool?

[Snow]

Looks like item C:


Also, if you remove the cam chain, you don't need the adjuster tool to replace shims - just make sure to measure all clearances before taking the cam chain off.

I figure, if you are going through the trouble to adjust the shims, why not also throw a new chain on?

[turbopete]

I made this a while back with help from a couple of other 200mph members. Might make it easier for you.

http://peterrimmer.myby.co.uk/files/shimcalculator.xls

[TopCatGr58]

Chain of fools!?

Originally posted by Snow
Looks like item C:


Also, if you remove the cam chain, you don't need the adjuster tool to replace shims - just make sure to measure all clearances before taking the cam chain off.

I figure, if you are going through the trouble to adjust the shims, why not also throw a new chain on?

Hey Snow,

That's not exactly the best info! Once you remove the cam chain, then you need to remove the cams WITHOUT turning the engine. THEN you can remove/replace the shims without the special tool. Then you need to ensure the proper timing to replace the cams and chain, OTHERWISE, rotating the cams with the head on, and the crank NOT turning will lead to a higher probability of bending valves. Also IF you do want to spin the cams, make sure you have removed one of the cams completely, otherwise when you turn the other cam, you will DEFINITELY bend a valve or to!!

DAMHIKIJD!!!!
T.C.

[Snow]

Heya TC,
Perhaps I should have been a bit more verbose in my description - yes, definately do *not* turn the motor once the cam chain is off...it's bad like crossing the streams. I just mean, if you measure each of the shim clearances before you remove the chain, then you can just pop out the old shim and pop in the new ones while the cams are out. I personally didn't have any problems setting the timing going by my manual, but perhaps I was just lucky.

[randy]

Resetting the cam timing is not all that difficult, the yammy engineers got this one right, the marks are clear and the procedure straight forward. But then I've time many a motor in my day. If it's your first time, triple check your work before turning the crank.

I always pull the cams to change shims, it's a lot less frustrating than that stupidly engineered Motion-Pro tool.

[turbopete]

One shpould always make two full rotations of the engine by hand after working on any part of the cam train. It's the most basic of checks, and saves so much potential time and money replacing valves or even pistons.

[scappod]

shims

So if what I am reading is correct then if the shims are not the right size then the bike won"t have the required compression to fire? So the shims give the motor it's compression?

OMIGAWD am I cornfuzzed!!

[Ken Talbot]

Sort of, but not really. The lobes on the camshaft push against the shims, which push against the valve lifters, which push against the ends of the valve stems. The shim is where you adjust the amount of slack in this train of parts. There should be a small amount of clearance in there, between the shim and the cam lobe. If it shimmed too tight, there could be no clearance left at all, and the valve would never actually close. If the valve cannot close, you won't get any compression.

[scappod]

Okay Thanks, I guess I need to pull it apart to see what the clearance is.