carb tuning

[mike75925]

how much bigger is your main than than your pilots? i have a 95 main, and currently running a 45 pilot. so the main is just over twice the size of the pilot. seems i should change the e-tube or something. should they really be this close, or does this mean i need a bigger bore carb?

[jr dragster Tyler]

My go kart runs a 12.5 pilot and a 130 main. My sled runs a 17.5 pilot and whopping 300 mains per cylinder. My buddies piston port 340 sled runs like 35 pilots and 200 mains.

[mike75925]

wow, that's a huge difference. what size carb are you running on the kart? the rhino i just worked on has a 150 main and a 40? pilot. the main is dictated by rpm right? when i first tried to crank my 'pos' after installing the 45, i forgot to reset the screw. i almost messed up my shoulder. she runs up nice but it got too dark to be sitting there doing plug reads. so it will sit over night and i will check in the morning.

[jr dragster Tyler]

I'm running a 22 mikuni on my kart. Main jetting isn't really determined about what RPM its going to run, Its mostly just determined by how much air/fuel the engine wants.

[mike75925]

yours is fully moded though right? do you have bigger valves?

[modelengineer]

20 pilots, 60 mids/starter, 145 mains
x 2

[1992suburban]

.020" pilot .036" main with stock Etube RUNS GREAT

[jr dragster Tyler]

yours is fully moded though right? do you have bigger valves?

Stock size valves.

[mike75925]

you are at about the elevation (ontario is) as me. but i wonder if our air is the same consistency. yours is colder and drier. hey burban, do you know the jet sizes off hand? and you are refering to the stock carb right?

[1992suburban]

I drilled them myself.. stock carb yes sir.

you can convert them into metric.. if you want but 91 main?

[mike75925]

i looked it up, that's just over a 50? if correct, it must thump at idle

[1992suburban]

sounds NICE.. I posted a vid I thought

[mike75925]

do you remember the thread name?

[1992suburban]

http://www.diygokarts.com/vb/showthread.php?t=6365