Cold weather jetting??

[yellowWB400ex]

I live in NE Wisc and it just snowed a ton and now my quad runs like SH*T!!!. I have a 42 pilot and a 160 main screw 2.5 turns out with the R4 system and no air box lid. The box filled with snow, It ran horrible. Then cleaned it out and put the lid back on and it still ran horrible. I think its the jetting but not sure. It would pop when you let off the throttle and it wouldnt idle. Please help. Oh ya its any wheres 0 to 32 degrees.

[12blaster34]

go up one size on the main jet

[zephead400ex]

If it pops when on decel, your running lean. Up the main jet, trial and error.

[throwinitup]

cold weather will always make your bike run leaner...id be careful about lettin that thing load up with snow..i would put the lid back on and drill like 10 5/8" holes in it...bump up your main like those guys said

[yellowWB400ex]

I rode it tonight and now it back fires blue flames only when your not on the throttle. Like it has to be W.O.T in order for it to run good.

[throwinitup]

wow put your box lid on, see if that might help. or rejet to a 165 or somethin...how do you like your R4? ive heard nothing but good about them...i think WB made a mistake discontinuing them..that was the best thing they had goin for them imo..

[yellowWB400ex]

I love the full system I got a hell of deal second hand only used a month for $240 he also had a Big Gun before this and he said the Big Gun had more low end but I think the R4 is great. Anyways I think that it is loading up with fuel though but would it act like that if it is running lean. It does idle but if you ar riding you cant let off the throttle completely. I was running it with the lid on but the filter was kinda wet and dirty but i dont think it would act like that. Im trying to figure this out before the weekend.

[throwinitup]

hmm im not too sure...4 strokes dont load up as bad as 2 strokes though,hell 4 strokes hardley ever load up at all...start doin trial and error...put a new plug in clean the fliter real good and see how it is. read your plug. white: lean u should know that though...if it is running rich or lean then rejet it you should be ok then

yeah id say u got a good deal on your R4 i got my BG for $175...it's cut down to about 8" long so it has even more low end...it rips for sure! if i werre to do it all over again though, it would be HMF or R4...but i still love my big gun

[yellowWB400ex]

I was thinking could it be the needle jet position. I didnt change that when I rejetted. This is makin me angry:mad:

[zephead400ex]

Have you tried to change your main jet yet? Don't mess with the needle yet....try the main. Oh, and getting pissed while rejetting doesn't help:)