KR-1S.co.uk Forum

Hi Despite the trials of getting rotors off, I have a question reagrding bigger pistons. My KR came with 2 S engines one good (except for the ignition system grrr...) and one with barrels that had been ham fisted....

The noog that owned it before me took the top end off to "de-coke it" coz he heard that all 2 strokes need this doing.... Unfortunately for himself he has the mechanical ability of an ameoba. He cleaned the head with a wire brush and then put the barrels on, only he didn't fit the ring gaps over the pegs, and just forced the barrels over the jacked out rings. He said he thought it should be like that. Kicked it over a couple of times until it wouldn't kick over any more.....

So I have a pair of barrels that look like a relief map of the Grand Canyon. I have found a place here in Aus that will make new Iron liners for them, but I need a source of bigger pistons with about the correct pin to crown height and pin size. The rest doesn't matter as the pegs and skirt length can all be fixed.

I reckon it will go out to about 60 or 62mm, but I cannot find a piston that suits.

Anyone got any suggestions?

Cheers

Get in touch with Stan Stephens he sells a 300 kit for the KR

300cc's ???

I think I have a better solution that that!!!

With a bit of help from Vince on the RGV list I think I can make RG200 barrels go on with fairly minimal work.

These are 66mm std and can go to 68mm with wiseco lightweight pistons.

There is an option to get some 69mm pistons but these may be heavy.

This (68mm) makes 350cc.........

I have a KR1-R set of carbs etc, so all I need to do is set it all up and get some pipes made.....

go for it and let us know how it works out

boring out the standard motor motor= tick tock tick tock
nothing wrong with the performance of a standard one anyway