Hesistation while goosing the throttle

[SUPERFLY 400]

I just finished putting my K&N power kit on. When sitting still i goosed the throttle from idle to W.O. and it hesitates for a second. I didn't notice it to much when on my test run. I did notice more pick up at low to mid range. I put a 165 main jet and the supplied dyno needle which is on the 3rd notch like the directions said. I have the K&N filter with precharger on with no lid on the air box. The directions said to turn your pilot screw out 3.5 turns i did that then went to 2.5. Still had a hesistation. I now have it set to 3 turns out. I dont know, but i did not change the pilot jet (still has stock pilot jet) i was wondering if this would cause the hesistation. There was no pilot jet in the Power kit, other wise i would have put a bigger pilot jet in since i had the carb off already.
I will soon be getting a fmf megamax 2, but i need to fix this problem first. Anyone ever experince this and what did u do to cure the hesistation upon snapping the throttle to w.o. if you open the throttle slowly then there is no hesitation.:huh

[crashinmatt]

i have the same kit and experienced the same problem. I bought a 42 pilot jet and it cured the problem, but i also removed the choke. I have not test rode my quad since because i broke my leg over a month and a half ago and cant really ride yet. since u dont have a pipe yet and if u keep the choke in, u might want to get a 40 pilot jet.

[SUPERFLY 400]

I'll get the 42 pilot, because i'm ordering my fmf megamax2 tommorrow. Hopefully I'll will have it this weekend. How many turns is your pilot screw turned out? Is there a special srewdriver or tool to adjust the pilot screw. Because its a pain in the *** to adust with the starter and cables in the way. (really no room for a straight screwdriver). This hesistation is driving me insane.....wait a minute i'm already insane. lol.
Anybody else ever have this problem and found a cure? Please help.:confused:

I have everything you have except for I have WB slip on. Put it back to 3.5 turns on the air screw.... put the FMF on and make sure you take the slack out of the throttle cable. When you test it again while idleing make sure it is completely warmed up to get the proper response. The fmf and taking the slack out should put you right where you need to be. I thought 3.5 turns was too much but after taking down to 2/2.5 turns I ended up with a bad idle.

[SUPERFLY 400]

hey Buck what size pilot jet you running? I'll set my pilot screw back to 3.5 turns (it also seems to much). Where would i adjust or check the throttle slack. I never messed with the throttle cable or adjustment when installing the power kit. but if it cures the hesistation, so be it...

[Wheelie]

Set you mixture screw to 2- 2 1/2 turns and step up to a #40 pilot, the #40 will look a bit different from stock, this is normal.

BTW--Are the jets in the K&N Power Kit Keihin jets, or other? Are the jets measured the same as keihins?

Good Luck!!

[SUPERFLY 400]

they are dyno jets. **** the directions said put the 170 main in for running with open airbox lid and K&N filter and it was recommended with aftermarket exhaust. well since i don't have the fmf yet i decided to go with the 165 main. if i snap the throttle from idle to w.o. it will hesistate or stall the engine (engine is already warm) but if i slowly move the throttle to w.o. it will not hesitate. :confused:

[Ketch]

Superfly 400 This what i did I ran a #40pilot an #165 main with
12 1" holes in the lid with stock pipe air screw i did'nt touch and it ran good. I also moved the clip on the needle one notch. I have added a powerbong and a q4 pipe and it still runs good. I think it is a little lean now. Also splitfire plug to. That's at 0 sea level to. i hope this helps.;) :)

[SGA]

You might try dropping the needle clip down to the 4th notch from the top. That should take care of the hesitation. Alot of 400s came from the factory with the throttle out of adjustment. With the engine off, open the throttle all the way quickly, you should hear the carb slide hit the top inside of the carb. makes a deep thunk noise. If you don't, slide the rubber boot off the cable at the throttle assy on the handle bars. loosen the locknut and adjust the cable out about a turn and try again. Adjust just far enough out so the slide opens all the way. lock the adjuster and your ready to go. If all else fails, make sure the carb squirter works. Engine off, pull the rear carb boot off , look into the back of the carb, open the throttle. you should see a small stream of gas shoot into the carb each time you open the gas. hope this helps.

i run the stock pilot w/ no lid on. i used the 170 too just like the directions said but it was too much. 165 is good enough. wait for your new pipe and see where your at after you put it on. if its still not where you want it then start changing the pilot. as far as the throttle goes, take off the boot cover right where it comes into the thumb throttle housing, loosen the lock nut and start it up... tighten it till you get instant response when you hit the thumb throttle then retighten the lock nut and put the boot cover back on.