piston question

[clive1]

Hi Guys, I have a set of Dave Marsdens pistons the 1030 kit that have come with no specs for reboring and unfortunatly dave cant supply any either so i will have to treat them as standard pistons ie skirt to sidewall clearance etc so my question is does anyone have the sidewall to skirt piston clearance info and where it is best to measure from any info here would be much appriciated my haynes manual just does not cover this at all.
cheers all
clive.
forgot to mention bike is 1977 z1000 A1

[Mark Tiller]

I would speak to Debbens

[ZedHead]

The Z1 manual quotes standard bores are 66 ~ 66.019mm, Piston diameter is 65.93 ~ 65.95mm and clearance is 0.060 ~ 0.079mm

[zed1015]

You need to measure at front and back of the piston skirt for clearance.
Forget about the side, it's the pistons that are produced oval and tapered for expansion not the bore.
Wiseco forged pistons for this size run at .050
std Kawa's are cast which expand more hence the larger clearance from cold.
If there is no specified figure quoted with the kit then the re-borer will use a chart to work out the optimum clearance for either the cast or forged pistons of your specific size.
Get the borer to cork hone the bores to the final size.
You will end up with a higher initial compression and shorter running in period.

[Z1B]

Last rebore I done was on a 1340 harley, 1 Thou was the clearance, took careful running in.

[clive1]

thanks a lot guys for your help i cant see them being any different to wiseco pistons so i think thats a good starting point.
cheers.
clive.