could the other bore be for the sleeve??

 

same # just multiplied twice
the final # is the one I'm unsure of, if Greg an all the better forum members wern't in Glamis or whatever they would correct me...double check with them

 

replace the figure pie with
.0078591


for example
BORE=70mm
stroke=64.9

70mmx70mmx64.9mmx.0078591=250cc
1985 kx250

sorry for like ten posts of bad info

 

your a genious!!! thanx jay

 

Hey shouldn't the figure .0078591 have an extra zero? It should be .00078591. I did your formula but was it turned out to be 1 decimal place too big. When I plugged the numbers in the formula it said a wolverine had a 3499 cc engine! Thanks for the formula by the way[img]i/expressions/face-icon-small-smile.gif[/img]

 

The formula is "BORE X BORE X STROKE X 0.7854 X # of cylender.

 

There is more principles then you know of when it comes to porting. Its not just about opening air passages, increasing air flow, and matching up the "holes". There are over 20 other things to take into consideration when porting a motor, whether it be a 2-stroke or a 4-stroke