Carb tuning help, sputters and pops at speed.

[Mountainwolf]

Hello Everybody,

Having a problem with the Shineray, I have done the air box to UNI filter mod and the exhaust has been gutted. Lowered the clip to the bottom slot and installed a 118 main jet. I am wondering if I need to make some adjustments on the air screw as it is in the stock pos. Plug is looking good, tan at the tip to darker brown at the bend. Any help is, as always, much appreciated.

Wolf

(Been edited for miswording on clip)

[elroyjetsn]

Shouldn't you raise the needle (lower the c clip) the enrichen the mix?? :?

[Mountainwolf]

Shouldn't you raise the needle (lower the c clip) the enrichen the mix?? :?

Your are correct, misworded I guess, I Raised the needle and LOWERED the clip. My bad! :oops:

Wolf

[red2003]

With that big of a jet (way too big, IMO) you certainly don't need to raise the needle. You are flooding out the motor in the midrange. I'd drop the needle at least to the mid position, and retest. Personally, I'd ditch that big jet and go smaller, if not stock. All you are gonna gain is less mileage. If you are gonna keep that big jet. I'd start with the needle in mid position, fuel screw out two turns. That sputter is probably the carb trying to transition from the stock pilot jet to the newer HUGE main. Kinda like the old Rochester Quadrajet carbs on the old Chevy 350's, heheh. Matt teh gas, about a 2 second bog...., then hold on! Showing my age here :D .

[usmc-mustang]

Yeah WAY to big. Anything over a 115 at sea level with lots of mods is way to big. you can drop 2 sizes for every 1000' elevation if I understand Keihens service manual. A 115 at 0' elev is a 103 at 6000'..