carb question

[jesse1004]

I have a 39mm keihin single carb with the pod and a trinity intake. My motor mods are a FAST low to mid port, bored around .60, lightened flywheel, advanced timing +4, dyna ignition, crank trued and welded, fattys, and coolhead with i believe 20cc domes. I was wondering if you guys think it is possible to run the carb out of fuel. When im just tearing around on the trails and half ass tearing it up everything runs fine. But when I like up to race and really open it up it cuts starts to cut out like its starved for fuel. I do still have the stock petcock on it. Do you think that needs to be changed? and also do you think maybe its a needle issue? jetting seems to be pretty damn close, so its throwing me for a loop. any help would be appreciated.

 

thanks in advance

[Banshee0028]

I have a 39mm keihin single carb with the pod and a trinity intake. My motor mods are a FAST low to mid port, bored around .60, lightened flywheel, advanced timing +4, dyna ignition, crank trued and welded, fattys, and coolhead with i believe 20cc domes. I was wondering if you guys think it is possible to run the carb out of fuel. When im just tearing around on the trails and half ass tearing it up everything runs fine. But when I like up to race and really open it up it cuts starts to cut out like its starved for fuel. I do still have the stock petcock on it. Do you think that needs to be changed? and also do you think maybe its a needle issue? jetting seems to be pretty damn close, so its throwing me for a loop. any help would be appreciated.

 

thanks in advance

WHAT NEEDLE and main jets are you running? Might have to adjust your float height although I have never done that yet.

[jesse1004]

not sure about jet or needle size. Jeff at FAST gave me a good starting point then I took it over to a shop with a dyno and he fine tuned it for me. Ive read a post on here about how some needles reallly kill your midrange. What needle would you suggest and where do I even get just the needle?