measuring stroke

John,

Two ways, take head off and put the piston at the bottom of the cylinder and measure the side of the bore or open crank case and measure from centre of crank pin to centre of crank shaft and then double result.

Mart> how do i go about doing this ?

If the plug hole is over the bore then just pop a piece of dowel in, rotate engine, marking min and max on the dowel. The measured difference is the stroke. hth Roland

centre of

is the crank pin the gudgeon pin martin ?

thanks - john

Nope. Its the big end. The distance between the centre of the big end and the centre line of the mains is the "throw" and the stroke is twice the throw. regards Roland

Thanks Roland, saved me some ink :-))

Roland and Celia Craven wrote:

No Probs :-) I imagined you'd be off out or making more pigeon fertiliser.... ttfn Roland