Tnx for the pics
KR-1R wrote:
the shorter skirt on the KX/KDX pistons puts it close (<4mm) from the bottom edge of the exhaust port at TDC
it would be 3.5mm and shouldn't be a problem according 2 reliable sources
It also means that on a B model barrel the siamese boost port (lower one) will be below skirt edge if it runs the shorter skirt
I'm running B's. but I don't thinck that has any effect, since the piston closes the top boost port.
Still in doubt as to what piston's to use.
first option was to use KX125 88-89, but 2 things bother me : if I can't make the insert's working, I will have to have another head completly welded up and make new chambers for the dished piston, but mostly since the flat part of the crown is only about 3.5-4mm thick (I thinck judging from pictures), not much room for squish.
secondly , YZ125 89, but compression height is only 28.50 (Mitaka source) or 28mm (Woessner source). on standard barrels might be ok (i.e. slightly raising ports), but my KIPS port's are already raised, which would give me exhaust timings off +/- 192.6° (28.50) or 194.8° (28.00). 192 would be ok, but from what I read/know, 195° would be too much (specialy for a road bike).
you happen to have the YZ Woessner to measure it ?
third are the
KDX125's
Do you sell piston's ?
there are some other Yamaha piston's but it's almost impossible to find correct data/keep them appart ... DT125(R), TZR125/250. You happen to have checked these out ? Woessner nr's 8002,8003,8006, Wiseco''s 679,684,236
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