Top End Clearances/Specs

[SpeedyManiac]

Need some quick answers, can't find them anywhere. What are the tolerances for piston/bore clearance? I've heard 0.06mm, but need max/min numbers.

Thanks,

Steve

 

[widebear]

one and a half thou of a inch min, max is up to you but I dont like to run more than .003 inch, two stroke sleds are known to run seven thou on fresh cast pistons.

 

[gasser]

Good info on this link (go to the long post) :
http://www.thumpertalk.com/forum/archive/index.php/t-430827.html

I have the official GasGas numbers somewhere I'll see if I can find them. - Ken

 

[gasser]

This is from the GasGas 2006 shop manual:

Clearance between piston and cylinder:
200 std:0.05mm , limit: 0.10mm
250 std:0.055mm , limit: 0.10mm
300 std:0.06mm , limit: 0.10mm
Ring Gap:
200 std:0.3mm , limit: 0.6mm
250 std:0.4mm , limit: 0.7mm
300 std:0.5mm , limit: 0.8mm
Cylinder Bore:
200 std:62.50mm , limit: 62.60mm
250 std:66.38mm , limit: 66.50mm
300 std:71.99mm , limit: 72.10mm

 

[GMP]

Also depends somewhat on what piston were talking about. I'm assuming the now OEM Vertex.