Raising puch cylinder

Richard Vestersund /
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Hello i got a many years Tomos tuning project. The motor is a Tomos APN engine with 5 gears (same stroke as puch) And i got transfers welded and recut for puch cylinder. Right now i got a PSR 70cc and its a exact copy of TCCD 70cc. I have driven it many miles but it has always lacked the top end. Then yesterday i checked port timings with a degree wheel and found out my port timings were

intake 136°

Transfer 110°

Exhaust 175°

Boost 100°

So yea Horrible! And it has been ported at exhaust 1.5mm and intake (skirt)

So i put 1 2mm washer to each cylinder stud and my port timings got much more suitable for a shifter like i have!

188° exhaust

127° transfer

125° Intake (will be ported more trugh skirt shortening)

BUT. Now when piston is at BDC the pistons boost port cutout is visable (not ported) about 2.5mm. Would this be a problem for performance?

I already have made a 1.5mm spacer and gaskets to use

Thanks!

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