hard to say man, the trail ate my GPS, I was hitting 74 prior to porting and going race pipe, clutching and gears, based on other quads I ride with I'd guess im at 80 or a little more on black top but i have no real accurate way to verify that. my pics are way out of date on the link in my sig.

http://s26.photobucket.com/albums/c107/conig/

despite the temptation, don;t let some one local cut your cylinder up porting these jugs take alot more work then most there probable used too and you would not be the first to have theres screwed up doing it that way, id suggest RCR, Bubba Ramsey or shoot me a pm they both do excellent work. definately get a wiseco, your on borrowed time man doing it now you can probable get a couple more years from your bottom end if you have maintained lubrication.

 

I wouldnt remove the oil injection unless you are going all out race mods.The Polaris system is way better than say Yamahas (as in the Blaster where removing is a must)

 

Conig nice scramblers, and bikes. Wow 80 mph thats sweet, i hope mine will make it there one day. That would beat just about anything, stock or even modded. The mechanic i know is really good, he used to race and make his own superbikes. He is really good. Have you rebuilt your bottom end yet? and what happened when your piston skirt broke. and i don't think i will remove the oil injection but its a thought because its always possible that something can clog it or a line can come off.

 

Ive done the bottom end, basically when the skirt breaks off it pulverises in the bottom end into a sand like substance and destroys the bearings, it can also crack the case's as well.