Join Date: Jan 2016
Location: Adelaide, South Australia
Motorcycle: 2001 GSXR600
Re: Adding compression
Ok, to answer OP's question (or 1 of them I think).
1.Get head off motor
2.Put Plastigauge or playdough or similar on piston
3.Replace head with gasket and tension.
4.turn motor over gently by hand
5.Remove head and measure thickness of afforementioned goo squished into valve pockets of piston.
That is your valve to head clearance.
Also a good idea which I've done with my 2 strokes is to use solder (like lead soldering solder for electical soldering solder) to measure squish clearance.
with head on:
1. remove spark plug
2. place solder in combustion chamber so it is hanging from plug hole and protruding into squish area of chamber (look up what squish area of chamber is, or ask that bloke above, his definitions are difinitively difinitive)
3. turn motor over gently by hand
4. remove solder and measure thinkness
that is your squish clearance.
On 2strokes this needs to be about 0.8mm or a wee smidge more for real high revving motors. Not sure what it should be on these motors.
If your expensive race-built motor has pistons kissing the head when assembled. Get another expensive race-built engine builder to expensively build your expensive race-built motor as it WILL explode in a spectacular and amusing fashion upon running.
just remembered i'm reading an old thread so talking to myself.
Last edited by SheikYerbouti; 07-24-2016 at 03:58 AM.
Reason: im stoopid