Back up, who in the hell would polish before porting? If polishing is so useless please explain to us why it is so often done from car engines down to our quad engines. I've got a hunch that its a big deal for a reason.

Pay for the port and polish. Find someone to do it right, and it will make a difference.

 

Both of them have their place and both will add power. Your going to gain the most from the port work but there is no reason not to do the polish while the head is off getting the port work done, it's a waste not to. Like I said before, the port work will allow the head to flow a higher volume of air, the polish will also allow the head to flow more air because there will be less resistance giving the air flow a higher velocity and with head work, that work is only as good as the guy doing the job. I have seen some heads the guy doing the work screwed up and ended up losing power. Find someone good that knows what they are doing and someone that knows what they are really doing you are not going to get it ported and polished for $150 and expect it to be an awesome job, at least not on a 4 stroke anyway. Mine cost me about $500 and he is one of the less expensive guys on the raptors.

 

I paid $250 for the port and polish job on my Warrior head, but that's also only a 2 valve head so that goes right in line more or less with what you paid for a quality job on your Raptor head. The best thing to do is either a) send it to a shop that specializes on quad engines or if you have any machine shops close just call around and find out what they know. You have a better chance of getting a lower price with local shops, but you also have to read the people and be confident they know what they are doing--which means more risk of a poor job.

 

ok i found the info i was looking for

polishing for the sake of polishing is useless. you want to leave the intake rough( sand blast texture) to help in atomization of fuel. While you want the exhaust polished to help keep carbon from sticking

 

I am not sure about that but the thread wasn't about just polishing, it was about a port and polish. I have never had anything just polished before, IMO it would be a waste to go through the trouble and not do the port work and that is where your largest gains are going to be.

 

i never MENT just polishing.. imeant the polishing part of porting & polishing.. you took it as just polishing though

 

Yea Speedy, I took it wrong. I talked to my head guy and he said the same thing you did as far as the polishing goes and the carbon buildup on the exhaust side. He said the polishing helps keep a surface that the carbon will not stick to so it will not build up later down the road.
The polishing on the intake side is different between something that is carbs and fuel injection and the fuel injection is where my experience comes in (I don't know how to port and polish, just have had it done, I don't understand the movement of the air to feel comfortable doing it) but with fuel injection the injector takes care of the atomization of the fuel so it's not as big of a concern as with something that is carbed.

 

Probably because flow dynamists is a tough study. We have learned a lot since 1957.

My intake ports look like a cat scratched them out. My exhaust ports look like a mirror.

 

I have a yamaha warrior 350 4 stroke and i was wondering how to do a easy port job that not as risky. if anyone could give instructions that would be great