newbiee n need help picking the rite jet for motor work n mods

[spdkilz0]

hey whats upp, well i have an 03 blaster that i am having bored .40 over and ported n polished as we speak. i just got boyesen reeds, reed spacer, fmf exhaust, k&N air filter with cover removed, n a oil block off kit, but wht i am wondering is what jet should i use i live at sea level n its currently cold here in N.Y.
also what else i should do ?

thank u

 

[tjscott]

jetting is a trial and error process

 

[daniel3877]

i have the same mods pretty much
start by turning out your air/fuel screw to 1 1/2 turns..
start with either a 290-300 main and if its like it is here(cold ) raise your needle by lowering your clip one spot...that should get your nice and rich...then do plug checks, check it at idle...after that go down the road through all your gears and when your at top speed in 6th hit your kill switch, then check your plug again. cocoa brown is the goal...then go from there...see if it feels boggy through your powerband. thats a good starting point..remember, RICH IS BETTER THAN LEAN TO GET YOU STARTED. if it's too rich put the needle back to middle position.(stock position) do more plug checks through out the throtle to find where it needs to be adjusted.

theres tips on plug readings and remedies under the DIY section(sticky : jetting 101 by randelator) its an awesome sticky !
any more tips feel free to ask.

 

[hickskateboarder]

idk if i have a weird bike or what, but i run a 350, a 290 or 300 sounds waaay to lean for a starting point for me... i'm at about 1500-2000 feet

 

[Wildcard2]

The builder you are using to do your portwork should be able to get you close on your jetting, if he has no idea...then you better save your cylinder from him and send it to someone who can give you a good base jetting recommendation

 

[spdkilz0]

he told me to go up 5 sizes and start from there so its at 290 n seems to be good i didn't finish the break in yet so well see how good it is. im just looking for a bigger carb now just don't want to spend that much anyone kno where or anyone selling one

 

[Wildcard2]

You can go up to a 28mm without changing the intake manifold, but you will still have to come up with a way to mount it to the airbox. What size are you looking for? I can do the 28mm Mikuni TM for $130 with cable. As far as your jetting goes, you need to do a series of plug chops to dial your jetting in. I believe it has been described on here before, but if you need hit me up and I'll walk you through it.