Banshee~

I would say a 340 main jet.

I would say 320-360 mains, 27.5 pilot, stock clip. By the way, ditch the lid to get the most out of the rockets.

sounds pretty chicken shit to me

I went from a pos lakota 300 to a banshee, no problems. I love my nossmachine head and fmf sst pipes post some pictures up of your shee.

A port job is going to be the cheapest way to make more power. Change out your pipes for some t5's or fattys, and maybe some 28mm carbs. Also a nossmachine cool head to keep your bike running cool.

Ive heard guy on ps talking about thickness of them might beeing a factor, but i dont have any idea.

whats wrong with octane boost????? nothing. Its not as good as running a mix of race gas and pump, but its cheaper.

Im thinking 380 mains, 30 pilots for stock stock carbs, but I think it would lower your main jet size if you bore them out.

Jim is the one who built your engine, so I would listen to him. Also if you havent, your going to have to ditch the airbox with shearers.

The yfz450's come out of the factory all ready hopped up for racing, but anyway who puts bikes in there signature that they dont own

No one is telling, but I think it has something to do with the thickness of the reed petals.

I used the stock pipe clamps with my sst's, got all 4 clamps on them to. Losen the airbox, so you can push on it to slip the clamps on (had to put some on backwards).

Should be pretty close, ditch the 2in1 and get some fatties and you will walk them. Beware a stock 450r with an HRC kit will smoke a piped banshee.

Is it bogging at WOT with the 290 main jet in? I think i put in a 300 main on my friends blaster with a b-1 pipe, vforce reed cage, and the lid off. If its not bogging with the 290 main in leave it in there, if you leave the stock jetting in there your going to blow your engine up.

93 atleast might even add some octane boost.

I would listen to dlnoss, and go with 21's for 93 octane. Stock is 22-23cc domes.

who is this builder?company?

Your going to blow your engine if you run it long with 320 mains. Im at the same elevation with pipes,filter, and the lid of and im running 320 mains. Order main jet sizes 340-380 and start with the 380's, if it bogs at WOT try 370 mains(continue until it doesnt bog). Once you dial in the mains, work your way down. I would try 30 pilots.

If you have service with cingular, read your bill every month or they will charge you for shit that you dident buy, or when your talking to another cingular user they might use your minutes talking to them. Oh yea, stay away from the motorola v551 model....its a piece, I know 4 people with this model and there is some software issues. Also, dont drop it into water or it will be screwed up forever

no shit, sit on the very back of the seat. One of my buddies has a predator with the airbox removed, rev box, and droped a tooth up front and it will catch my piped banshee on top end with his extra 1,000 rpm's. He would beat me bad if he could ride worth a flip

100 spoke rims and some tires made out of rubber

Who ported your engine? They can get you in the ball park, but I wouldent run anything under a 360 main with the lid off. Try what fastbanshee4u said, put the lid on, and that will make you 1-2 main jet sizes bigger so you can tell about were you are.

go to a yamaha dealership and they can order you one.

t5's work better with porting, so if you plan on porting down the road get the t5's. If not, get the t6's.

You should can run 20's at 1000 ft with no problems.