well the piston i was hoping to use is a FAIL, lol....
thankfully it was tested on some other bike and not mine.
after 2 or 3 weeks of messing about and trying different settings, alll they were able to gain out of these new pistons is a -2Hp (yeah, it lost power, rofl).
they expect that its due to the low quality material used... since as far as the shape is concerned, it should have been good. bigger bore (64mm instead of 62) and a slightly bigger head, increasing the compression ratio. anyhow, im sure there is lots and lots of research required to be able to build pistons that gain power over stock, something that this manufacturer obviously doesnt have enough of.
the mechanic then confirmed with three other workshops that they were getting similar results using these pistons (ie. drop of power).
soo.... i guess ill just leave the pistons alone, and get the engine ported and re-tuned for now, lol that should already add some ponies into the small stampede.
now im looking into the JE pistons. and wonder.... what piston would be best to use out of their available ninja 250 pistons (they have 5 to choose from!)
282cc... mmm...mmm...mm... anyone know if that is possible to bore up with the original sleeve? or does it need a totally new/replaced piston sleve thinggy? lol, forgot what its called
back to square one, research time, yey!