i am gonna install a slp air horn kit on my 04 pro xr 800 and was just wondering what you boy's run for jetting. i have the hot seat single and mbrp can and delta force III reeds. my elevation at home is around 1500-1900 feet. i am also going to install two 2.5" flow-rites. i don't want to remove the speedo for a bigger flo-rite, so are the two smaller one's enough and where do you guys install them on hood? thank's for any good info!

I dont have any flowrights in my 700, you will be fine with a 440 main on the coldest of days and wot for a 1/2 mile no issues.

wow, xc-mark you run 440's? i run 470's which i know is concervative and i thaught with adding the air horn it would balance out. i will have to see if i can lean it down a little. maybe that is why my 800 get's such bad mileage.

If you are running larger mains than stock, you are making less power. Airbox mod richens it 1-2 sizes approx. 440 is safe for multi mile full throttle, provided good fuel, even good 87 octane on the regular setting.

does that hold true even with modification's to the exhaust. i believe that the stock main's are 450's. maybe that is conservative from the factory. if i could get away with running 440's with the intake and exhaust mod's i have, that would great.

That is with an SLP or other single pipe, or any muffler.

440 are safe to run hard for a mile in a 800. I run 440 in my 700 but with a high compresion head and unknown fuel quality some times its easy to dial the tempaflow lean when I can get 91 fuel. 98% 0f the time its running 91 but the times I can only get 87 I set the tempflow rich and save the motor.