port and polish

[300EXer]

im about to do a few motor mods to my 300. pipe,k@n. and im wonderinf about p and p. wut r the ups and downs to this? how much is it gonna cost me? and can i do it my self?

[0240099r1]

around $175 and up if you have never done it you prob. want to get it done by somebody not saying you can't do it or anything theres just more involved than what most people think i spent around 12hrs on my head just to give you an idea........

[300EXer]

wut am i gonna gain? a lot of hp? or wut? would u say its worth doing?

[RED121572]

Porting and Polishing is expensive. Worth the power gain? I say no, just because its expensive.

If you dont have use of a flow bench, dont do it yourself. Dont pay anyone to do it unless they have a flow bench. Sure, anyone can grind the inside of a head with a dremel, but if its done wrong, you lose pwr.

Good luck!

[0240099r1]

do i think its worth it yes anytime i can gain any horse power its worth it to me but red is right if you let just anybody do it you could lose horse power thers way more to it than just going in and opening things up bigger is not always better here if your just into riding just put a good piston and cam and i think you will be very happy .......

[Scott]

You have 2 guys with 400s discussing porting the head on your 300. I'm not saying what they've said is wrong, but there's a couple other things you might want to consider before making your decision. The head on the 300ex is the same one that was used on the 250X. The displacement was increased to 282cc and it became the 300EX. The 400 head was designed for the 400, not a hand-me-down piece from another quad. With the increased displacement, the head on the 300 could be a restricting point for the intake. I have a 300, and I've also read several other people on here stating the 300 head is somewhat restrictive as well.

If it were me and I was rebuilding the engine, especially if I was increasing the bore, I'd get the headwork along with the pipe. But keep in mind that you can dump $3-4k into the 300 and still not be much stronger than a slightly modded 400.

But it's your money and your ride. It will still get you from point A to point B just fine with the factory head porting.

Good Luck.

[0240099r1]

port and polish can help on any engine no matter where the head came from or what size the motor is yes they flow pretty good stock but do to assembly line they don't have time to get the casting marks or blend the bowls etc its all in what you want and how much money you want to spend but scott is right by the time you dump 3000 in a 300 motor you could have bought a 400 but if you want to out run other 300ex's then build it, it may be worth 1 hp or 5 its all in what you want if i were in your shoes i would just put a 330 kit in it a cam hardened rockers and still have a very fast 300 but thats just my .02 ........

[300EXer]

thanks for all ur input. i totally agree that if i wanted something with more jam, i should fo got a 400. but im only 13 and i got a 300. and around here i've got the slowest quad. everyone has 400's,warriors, and a few have blasters. i sit beside a stock warrior and blaster. i wanna beat them. just off the line, i could care less about speed.

I wish i could afford a 330 kit. but like i said im only 13. and the only job i can get is mowing lawns(which is a waste of time). My parents said they'd throw in a few buckaroos to help me start racin. so i need some motor mods. i got 4oo ex shocks so i dont really need any suspension stuff.
And if anyone has any comments,please share.:D

[0240099r1]

don't worry about any porting right now save up your $ and just go with the basic stuff for now 330 around 130 plus boring and install start with what you can and soon you will be where you want good luck