If I get this: http://cgi.ebay.com/ebaymotors...%7C39%3A1%7C240%3A1318 what else would I have to do to make it a good running machine? Also, would I have to start using race fuel? Because as long as the gas can be bought at a pump (regular, mid-grade, or premium) it's fine with me. I just don't want to have to buy race fuel.

Thanks

 

i ran premium with mine works fine

 

My owner's manual says 92 octane....and that is with stock compression. Anything higher than stock, seems like it is going to need something higher.......

 

my yfz is 11:9:1 stock it says 92 octane

 

11:1 in a 4??ex is at the very minimum on 92 octane. It will run, but if you beat on it at all it will over heat and lose performance. I have a 426 in the garage that is 10.5:1. It is my wifes quad and when she rides it, it does fine. When I really thrash it, it starts getting hot. I have put a 50/50 ratio of 92/110 in it and can beat it till the quads come home.

You could do the big bore and then look for a fuel additive, or just remember not to beat it.

 

Dont get a big bore kit! They suck!