I see alot of folks doing these mods. I know that porting and polishing offers better airflow, but what does shaving it do? I am assuming in bumps the compression up. So, what will these things combined do in terms of felt performance?

 

yes as far as i'm aware shaving the head bumps compression.

now porting and polishing are a mix between a science and an art, especially on a 2 stroke. for example my engine builder "2 stroke performance" never went to any AMA and works out of his garage at his home but hes in his 40s and has been tinkering and tuning since he was a little kid with lawnmower engine go-karts. He has a 250r bored to a 330 and has ported it to give an almost linear powerband. polishing is simply removing the rough spots from casting and methods used to fourm the head. bumpy and brushed surfaces create turbulance in the air flow. a simple polish is to stop that turbulance. a port job its an artful reshaping of the ports into the head to increase flow and can change the way the engine runs. This can be for the better or the worse. If done properly amazing results can be had but if somebody does a shotty job it can ruin a top end and if they took too much out it cant be corrected with another port job you have to replace the cylinder... What kind of bike do you have? what mods have you done to it so far?

 

2006 Wolverine 350. Only thing I have had time to do is put a UNI on it. I have bought FOUR other quads this month (two are Christmas Presents, the other was/is to sell, and I have a Jet Moto Coming. I wanna see what the deal is with them...) so the cash flow has been tight too...

 

yes shaving the head will up the compression a little but you dont want to take off much due to piston to valve clearance being tight on most quads.
as ctatv said porting and polishing a head helps with the flow of air into a motor, it does make a difference in the way a bike revs and how much of the fuel it burns inside the combustion chamber.

 

Head work and Porting on a 2 stroke can make a huge difference. In fact, after a pipe that is where all the power is to be had. After install an aftermarket pipe, a 12-15 HP gain can easily be made with banshee's just from porting and head work.

For the 4 strokes, especially the newer 450's porting does help, but not to that degree. 5 HP gains are huge, but that also requires larger valves with the porting.

 

im on a 2001 wolverine before youd have to worry about shaving the head and porting you would want to do :slip on exaust, aftermarket air filter, new camshaft, and higher compression piston

 

I agree with ctatv, first the exhaust, camshaft, piston, and air filter. Then if your not happy or you want to do it while it is off have the head ported and polished, I wouldnt worry about shaving the head until I needed to do it at a rebuild.