I have a question that hopefully one of you carb gurus can help me with...
I bought my 300ex in the beginning of the winter and it was always hard to start, but i thought it was just because of the cold weather. It came with an aftermarket pipe when i bought it, and then i bought a supertrapps pipe because the other (DG) pipe was too loud. Since it had that open dg pipe on it i'm totally sure the previous owner jetted it.
Now that its about 50-60 degrees out the quad still starts hard. Once the quad has warmed up it idles, and runs perfect. It also starts right up once it's warmed up.
BUT until its warmed up it wont idle, and tends to "sputter" and stall. I have to keep reving it to keep it running or it will stall.
I've checked the plug (and installed a new one last week) and it is kinda black. (rich).
My question is what jet (pilot, main, or needle?)do i have to change and how much smaller of a jet should i get? (should i get a smaller jet, or what?) Do dealers usually carry pilot jets for these quads or will i have to order them?
Thanks in advance

 

actually my guess is valves, they are probably loose..this will cause hard starting with a cold motor.

 

I dont think it's the valves because then it would start had when it's warm also. It'd be your pilot jet that might be lean but i dont see how that'd make a difference. Try using a hotter plug then what you're using now. That should help it start better. I used to run NGK DR8ES but I seemed to go through those quick and now I use a DR8ES-L or a DR7ES, just depending on whats available at the moment.

 

That happened because my valves where too loose once i got them adjusted it starts fine. And also what kind of gas are you running, regular is the best for cold weather because it doesnt take as much heat to catch as high octane does.