Jetting

[DEAL]

well .. I've had my 416 together for a few months now, it runs amazing has tons of power but I am having alot of fun with the jetting.
Right now I am running a dyno jet kit with the 170 main that comes with the kit , the dyno jet needle and a 42 pilot jet.
This is what confuses me.
The kit recomends this jetting setup for an aftermarket exhaust system, no air box lid and a stock motor.
When I origionally put my motor together with this jetting setup the plug was a nice brown color (even with the 416).
The motor runs perfect, it doesn't bog out of corners or anything, I don't think my jetting is 100% perfect but it still is working pretty well.
But the other day I decided to do a plug check and my plug came out black...
There hasn't been any major changes in weather from when I was getting a brown reading to now... I'm not buring any Oil either.
I don't understand, can someone explain to me what is causing me to get a rich reading on my plug now?
I probably shouldn't mess with it since the quad runs fine but I have lots of time on my hands.

[cals400ex]

i have read numerous times that the jetting instructions that come in the kit are a ways rich. if the dynojets are larger than the keihin jets like i read, i wouldn't run anything near a 170 in my motor. on my 10.8:1 406, stage 2 hotcam, x-6, fcr, modded airbox lid, uni filter, etc i would run around a 165-168. i think your hurting a lot of your possible power by having a jet in too big. also, you could be rich on your needle clip position. just a suggestion...