Cold weather... fresh rebuild not liking it

[monkeydude36020]

Ok as most of you know I finally got my problems solved with my 400 not running after the rebuild, had the carb cleaned and there was a fault in my rebuild which is fixed now... The quad starts fine cold with the choke on. I will idle forever if the choke is on half but no matter what I do to the damn thing wont idle on no choke. Ive tried adjusting the idle screw to the point where choked it running at least 2000rpms and it still wont idle with no choke. Its also falling on its face while riding around 2500-3000 rpms. It wasnt doing this the day I got it back from the shop. It would run all the way to rev limit no problem and had full range of power in every gear. Now I cant hardly get it out of 3rd. The only thing thats different now is the weather... It has dropped about 20* since I started it last. Its about 45-50ish outside and Im thinkin maybe its just not liking the cold weather. My question is... should I jet it? Its on factory jets with a stage 2 cam, the 11-1 piston, hmf pipe, and monster coil. I wanted to see how it ran first before I jetted it, and it was fine in the warmer weather but now its pretty bad. The only other thing I could think of causing the power loss is the cdi box and I wasnt having any trouble with it before the rebuild so thats not likely.

If I jet it what should I start out with? and Will the 42 pilot fix my idling problems?

[tri5ron]

Up the size of your pilot.

you don't say what your pilot is now, so a 42 may be all you need if your currently on a 38 -40 (Kiehen), but I doubt it.

go get a few pilots up to a 48-50 (Kiehen), and you should be able to get it dialed in very well.

use KIEHEN jets, they are available at the Stealership for about $4 each.

btw, did I mention that they should be KIEHEN jets ?
(the sizing for Dynojets is not the same)

[monkeydude36020]

would the pilot be causing my top end power loss?

[rocky_mtn_honda]

Originally posted by monkeydude36020
would the pilot be causing my top end power loss? ...likely not, the pilot controls your idle and startup.
get your jetting money, then go from there on the power loss.

[F-16Guy]

If you haven't re-jetted after the rebuild, your jetting is WAY too lean. Go get yourself a 42 pilot and 160, 162, 165, and 168 main jets. You can get them from your local shop (if they have a clue what they're doing), or you can order them from www.jetsrus.com. Install the pilot and turn the fuel screw out about 2 3/4 turns. Start with the 168 main jet. Warm it up well and take it for some full throttle passes to get a feel for the power. Next, try the 165 main and do some more passes. If you feel a definite improvement, try the 162. If it's about the same, stay where you're at. If it's worse, go back to the 168. The idea is to start with a jet that is too rich and work down to the correct main. The main jet should be selected based on full throttle performance, since it is what meters fuel from about 3/4 to wide open throttle. Don't worry about the needle, it should be pretty close in the stock position.