i have done a little porting in the past but this 250 trailblazer motor im afraid i dont know much about (piston port vs reed valve) is the porting principles the same, i ordered a weisco from ritter today and gonna bore it .020 and thought while i had everything apart and cant afford to have ritter sell me his i would do a little work on the jug, is it the same as what im used to on a reed valve motor, are you guys just dropping the intake and raising the exhaust? is anyone messing with the transfer ports? how are you guys getting the power, im only looking for reliable information, and to those of you that do this to make your living i dont care to have all the specs, i just want to make sure im not gonna jack up a jug, im not shooting for anything radical, just a little here and there, any help at all would be great....

thanks
james

 

If you start dropping the intakes and raising the exhaust you are asking for a lot of trouble. The bike will not have any bottom end. Porting is delicate work, but I can tell you that you want to widen the intakes and widen the exhaust. You can raise the exhaust 1mm also. Transfer work is always beneficial, but you have to know what your doing with roof angles, timing, and where the flow is directed. That's all I can tell you without writing a book in detailed explanation. The rest is up to you. Bubba

 

hey bubba, ive been wondering this for a long time now. how did people like you dennis learn to port? it seems to me that u would need to be sitting and watching someone to learn. ttyl,
scott