D.I.Y. porting

[DAVE14]

I was just cleaning up my 400 ex head & I can clearly see cleaning up all the casting flash would open it up a little but in a true port job how much material is removed what shape etc. & how much will this help a 12.5 to 1 440 ?

any pictures sites or info would be greatly apreciated!

[400exrider707]

Porting is an art that takes a lot of skill to do. Most people are pretty capable of doing a clean up, but to do more advanced porting like changing the shape and creating a good flow, is probalby out of the question. You would be better off sending out to a reputable engine builder. A good port job, a bigger carb, and a full exhaust and cam will make that baby scream!

[wilkin250r]

I'll echo that statement. A simple clean-up job is fine, and certainly will give you some small improvement. But actually removing lots of material and changing the shape and flow characteristics is best left to a pro.