In a week i am gettin my quad bored and stroked (.40) over, and installing a wiseco wit a new top end. Will i need race gas?? what is the best kind and where do i get it??

 

My 400EX runs fine on 87 octane. You might find that 92 octane will be needed after your bore. I co-own a performance shop for ATVs, and are used to telling people to start using 92 octane fuel after mods. But you're just going .040 over which I wouldn't think would'nt change anything.

 

Why are you going .40 over? Unless it's bad you should just go a step at a time .20 over.

 

what does .40 over make the cc's? 330 or what?

 

It would make it 322. I am doing it cause i need more power. I am beginning to race MX. So i need more power to get over jumps and stuff.

 

Going .40 over can't make a 322 out of a 300 I would go .20 over so the you will still have room to bore again when it comes time. You won't b able to tell any power diffrence between going .20 or .40 over. You will will probably be ok running 93 pump gas, but it wouldn't hurt anything if you mix a little octane booster with it, since you will be running a hogher commpression piston.

 

You want power you say, have you thought of a cam, thats where youll get some.

 

Yes, i thought about a cam. But i don't want to have to crack the case. That is alot more money on labor than i am willing to spend. Bore and stroked, ported and polished is enough i think.

 

If you are getting the crank stroked it will no morer trouble at all to put a cam in it. Oh yea if you stroke it, it wil prolbably be a 322.

 

The need for race gas (higher octane) is all relevent to how much compression you have. Without knowing that I couldn't really tell you. If anyone doesn't know why this is say so and I will go into a big in-depth post on why higher compression=more power, and a need for higher octane ratings. I would do it now, but I am tired from having to dig myself out of mud three times today and am going to bed now.

Oh, Boring something 40 over doesn't mean that you are getting an additional 40cc's. It is when you bore the cylinder out (it's so small of an expansion it has virtually no performance gain) to remove scratches and other imperfections from the cylinder. It is also used for replacing worn out engine parts.