Honda 250r Porting Questions

[TrikeMike]

I kinda understand porting, but don't understand when people say it was ported for TT or cross-country or MX. What is the difference with the porting and what do you think is preferred for Trail/MX riding?
Thanks.

[Mr. Sandman]

Porting involves reshaping and or enlarging the exhaust and intake ports to increase flow in different combinations which affects the powerband in a variety of different ways. Usually it also involves decking the head and cylinder to increase compression.

This in turn determines what works best for different types of racing or riding situations, ie. mx, cross country, tt, woods, hill shooting/drag racing, etc. When done correctly the powerband hit and hp increase can be an amazing difference over stock. When done incorrectly, the results can be disasterous for your motor.

It's an art and at the same time it's also a science. It's definitley not something you want to try unless you have a good supply of cylinders and motors to experiment on (I don't care what the guys that sell porting 101 dvd's on ebay say)

[TrikeMike]

I have been looking at buying another 86 motor, its just alot of them say "ported or mild porting" and I wanted to know the potential for error or bad motor. I also was considering having mine professionally done but wasn't sure the benefit justified the money. Sounds like "if done right" it would create a hell of a ride.

Thanks.