400 ex 200main jet?

[420exJuggalo]

i just had my motor done by advmachining. up in pa, i live in jacksonville fl, but i had him do a 420bore kit ,ss valves,multi angle valve job,port and polish,stg2 hot cam,hot rod crank,crf450 timing chain, w/hmf full exhaust,open air box. and he told me to put a 200 main jet in. i havent even started it up yet .but its ready to go almost, im waiting on the lil o-rings for my oil lines to the case,i was just wondering what you guys thought. i left the pilot and the needle clip alone, im pretty much at sea level maybe 1k foot above if that,should a 200 work, i just want to be able to start it and have no problems,since its a fresh motor and hasnt even been fired up yet, i jst want things to go nice is all im getting at. let me know what yall think.

[gojk]

Originally posted by 420exJuggalo
i just had my motor done by advmachining. up in pa, i live in jacksonville fl, but i had him do a 420bore kit ,ss valves,multi angle valve job,port and polish,stg2 hot cam,hot rod crank,crf450 timing chain, w/hmf full exhaust,open air box. and he told me to put a 200 main jet in. i havent even started it up yet .but its ready to go almost, im waiting on the lil o-rings for my oil lines to the case,i was just wondering what you guys thought. i left the pilot and the needle clip alone, im pretty much at sea level maybe 1k foot above if that,should a 200 work, i just want to be able to start it and have no problems,since its a fresh motor and hasnt even been fired up yet, i jst want things to go nice is all im getting at. let me know what yall think.

That sounds a little fat. But it should be good to break it in a little on the rich side. I think I have a 185 in mine right now. I am at about 1500 ft

[pro-rider46]

Originally posted by gojk
That sounds a little fat. But it should be good to break it in a little on the rich side. I think I have a 185 in mine right now. I am at about 1500 ft

You have a 185 in your FCR?! the 06 450rs with the FCR only are 70pposed to have around 170 with a aftermarket exhaust

[gojk]

What are you saying???


They are 2 completely diff engines. There is no way that because a 450r uses a 170, that a 400ex with a similar carb would have to have a smaller jet. There are too many variables to assume that. For 1, the 450r's vacuum that the engine creates could be far greater than that of the ex, therefore a smaller jet will still send more fuel into the engine. Just because you have x size of jet doesn't mean you are going to get x amount of fuel into the engine. Velocity through the carb makes the most difference in fuel supplied through a jet.

[big95xj]

My buddy (brad200615) has a 416, port and polish, stage 2 cam, no lid, and sparks x 6 pipe. He just got it and it has a 200 in it. He lives in Daytona Beach by the way. But anyways its way to much, if hes just cruisin along at about half throtle the thing spits and sputters and sounds like crap. But once he opens it up it runs great. I think its right when it switches to the main for its main fuel supply that it does this once its off of the transfer ports, idles great, runs great if its pegged but cruisin half to three quarter throttle it is horrible.

[lpmaster]

if your on the stock carb, you'll never ever need a 200 main. if your on a 450r carb a 200 mian isnt uncommon @ low elevation. even @ 200 main on my fully ported and camd 440 kit with a 450r carb it was a slightly rich (which is what i wanted)

[420exJuggalo]

good news,bad news..
ok i got it running great it has a 170main btw. with a 38pilot needle clip at 3rd from top. ran like crap until i took my airbox lid back off, but i finally got oil in it ran it, and low and behold theres a leak, turns out its from ups,the company that shipped it. i looked at the spot which is under the exhaust port below the motor mount ,it turns out my box has a puncture wound on it the same spot where the case was sitting on the bottom of the box, im not shure what to do now, im waiting for monday so i can call al at advmachining. i know he had the package inshured, but i got it a week and a half ago. and finally just now got it running a going today with oil in it. i dont know if there is some kind of deadline on how long you wait after you get your package, but i was thinking maybe i can j.b. weld that b!tch or possibly have my g.f.'s dad's friend weld it with some kind of special welding agent, let me know what yall think