probs with the 416, jetting?

[YZROOSTINYA]

this past weekend my quad is acting a little funny

jetting is 170 main stock not dynojet
4 clip down on needle(stock is 3rd or middle)
42 pilot
2.5 turns on airscrew

it pops slightly on decel but i think itsbecause there is a sligh leak where the header meets the pro meg


but know when i crack the throttl ein lower r's in hesitates and pops. wasn't doing it before. in mid to uppers its fine. only really happens if its more than 1/2 throttle it seems. my plug is PERFECTLY tan both times i checked. the insulator is tan all the way down. i have about 32.7 hours if i am correct on the hour meter(top end), about 75-100 on the whole quad.

i was thinking my carb is dirty maybe and a jet is clogged? or do i need a lager pilot like a 45, would this be caused by being rich or lean? no choke, stock head, no porting, just mods in sig


some holes in airbox lid

k and n

what should the air screw be set at?

i am going to pull the carb this weekend. since i wont be riding since it just snowed 20 inches were i ride at.

plus i need tires bad.

its about 30-40 degrees ot right now. i will prob go to a 165-168 main in the summer

[300EXrider02]

i think it is actually 3 turns for the fule screw....dont know if that will help, but if you need tires i got some rear razrs...22/11/9 no wear, no ver very little, i can take a pic if you want...there 4 ply, and hold up awesome, i jsut wanted 20"....i got some pics of the quad john u gotta check em out...josh on bbs sized em down for me...here is one, i jsut wishd it was washed, polished, and wd40ed:D :D

[300EXrider02]

....

[gojk]

Check your vent tube and the fuel line into the carb. it sounds like it is running out of gas.

[MC80]

check your plug because it sounds like you went a little over kill on the jetting. If you ask everyone else about there jetting on a 416 even with a high comp piston they are usually running a 160 - 165 and only a 40 pilot with the choke removed. if you try to give it straight throttle off of the line does it want to die? if it does and then the plug is loading up and that is where you would get the backfire. There is a diffence in the sound of a lean pop..
let me know if this helps but i would definetly check out the plug.

[BadA$$440]

He already said the plug is Perfect.

On my 416 i got : 160 main, 4th clip down on needle, 38 pilot, and 2.5 turns out on fuel screw. Runs perfect for me. No hesitation at all. All though it pops a lil on heavy decellaration.

[YZROOSTINYA]

i pulled the carb and cleaned out the ports

i moved the air screw(pilot?) to 3 screws out from 2 1/2. cleaned the filter and it runs fine when hot but still dies at idle before its hot and it was fine before, it stopped popping though

i am gonna replace the head gasket and carb insulator o ring, i think it is leaking some place

i also got the silencer to stop leaking where it meets the head pipe and i replaced the header gaskets. gonna clean it and tear it down, well see what happens