need a little help

[j-bird618]

alright i just rebuilt my 98 blaster. had it built with a 240 kit,a 3 mil stroker crank,port and polish and reworked head. it has a fmf fatty pipe and power core silencer and im running a uni stage 2 clamp on filter on a 35 mm mikuni carb. problem is i cant get it to run without the choke off. with the choke on it will run and idle fine. any help is appreciated. thank you

 

[fioz600r]

Sound like you are running lean. You should check your jetting.

Is the airfilter right on the carb or did you use a volocity stack?

 

[j-bird618]

it is on the carb. i know that the main jet is a 180 do you think i need to go bigger

 

[fioz600r]

First I would put a volocity stack off the carb to the airfilter.
Running the airfilter right off the carb the air going into the carb isnt smooth going in it is all scattered and going in all differant directions. With the volocity stack on the air goes onto the carb in a smoother path.

What jetting did your engine builder tell you to start with?

 

[j-bird618]

the shop that i had build it didnt tell me any size jets. i just assumed it was good to go since the carb was on the bike to begin with. so was the 240 kit-just needed a new piston and rings.

 

[fioz600r]

So the Blaster had all the mods done when you got it? You just had a new piston and rings put in?

 

[j-bird618]

all except for the head i had it milled and reworked. the cylinder was ported and polished but i had it cleaned up a bit.

 

[coastie903]

The main jet is a 180? That's probably WAY too small... a stock jet is 230... I don't know how the Mikuni jetting is compared to a stock carb, but I'd bump that up for sure... it's something you'll have to play around with... get a good assortment of main jets, and do some plug chops until you get it right.

 

[j-bird618]

sorry guys upon taking a better look at my jet it is a 380 not a 180

 

[fioz600r]

A 380 in a 35mm thats huge. I think you should drop down on the main with a 35mm carb.

I think guy with carbs that size run like 150 mains.

So I guess you are too rich not to lean.

 

[j-bird618]

i appreciate the help gonna try putting in smaller jet and put a velocity tube on

 

[fioz600r]

Let us know how it works out bro................