1987 250WR piston or alternatives

Is that a power valve piston vs non power valve piston RUF?

Its a WR so non power valve.
I read on an old magazine that the power valve was made only for CR motors.

Yeah I believe you are correct, but it has been stated that the power valve pistons can be used in non power valve motors, do you or does anyone else have a pic of a 87/88 250CR piston for comparison purposes?

my last pic shows the old one for non power valve motor and the new one for power valve.

Excellent! That's what I meant, just worded it poorly.
Tony

Do the late 250's with the 72mm Stroke use the same Connecting Rod as the earlier 250's ? Or do they use a Rod of there own ?

same rod, different crank cheek

72mm is the stroke the current (and for a number of years) crop of 250 two cycle competition bikes. It looks like 70.8 is the longest stroke for "250" two stroke bikes in this section.

You also may be showing Woosner vs Mahle. In the 430 pistons the pin is offset for the woosner but not the Mahle, the cut outs at the transfer are somewhat different location.

I have bought from him as well. He has kept that stuff in his shed because they were not that rusty 4 years ago when I picked up a set of 1987 forks

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