I'd like to know what jetting you guys are running. Especially you guys with pipe and piston mods. I've got mine back together with a bored cylinder and an FMF gold series pipe and have a slight smoking problem. I think this is due to incorrect jetting, though I am not sure.

 

CALL OR EMAIL FMF AND ASK THEM FOR JETTING SUGGESTIONS. I don't understand why so many people are relunctant to do this. Be sure to give all information reguarding your quad: type of carb? porting? headwork? airbox mods? reeds? etc. When you have a pipe, talk to the techs at that manufacturer. If you have a ported bike then talk to the shop that did the work. THAT IS THEIR JOB!
That being said, a smoking problem is rarely assosiated with incorrect jetting. What premix oil and ratio are you using? I hope you aren't following the manufacturers recommendation of 20:1! I use Klotz R-50 at a ratio of 40:1 in my LT500. The richest you should be running any decent two-stroke oil is 32:1. I used to use Yamalube R (I could be a little off on the name) and that stuff actually smoked less than what I use now. Whatever oil you are using, try something different at a ratio between 32:1 and 50:1. If there is any other information you can provide on your problem, let me know.

 

Golden-Spectro at 32:1

 

I assume you realize that the Quadzilla is going to smoke more than the other atv's you have - afterall, it is a two-stroke. Do you feel that it smokes more than other racer type two cycle atv's?

 

I also have an FMF gold series pipe and silencer. My cylinder has been ported and is bored +.040. I run a Kehin 38mm PJ and last weekend in the dunes (Glamis) I ran a 198 main, DGJ needle with the clip in slot 2. I run Maxima Super M oil at 50:1.

Btodd is spot on; you should call FMF and they will suggest to you what jetting to run. However, you should be able to get your jetting set without the call. All you need is an afternoon, a bunch of main jets and needled, 17mm wrench and a 6mm jet wrench.

 

Thanks LT5001987

 

Slinger, I hope you realize that if you don't have the same carb as LT5001987 you can't follow the same jetting specifications. If you have the stock carb it is a Mikuni TM 38.

 

I do know that the stocker is a Keihin, a TM38SS, that was the reasoning behind my asking just Quadzilla riders. Yes I do realize that a 2 stroke would smoke more than a 4 since a 4 shouldn't smoke at all. I have had this Quadzilla for three years and while it has always smoked slightly it just seems worse after this last rebuild. Today, after a little warm up it didn't smoke as much and in fact at times didn't at all. The reason I question my jetting is due to the smoke and I feel it is running a little rich. Also in mid-throttle the machine seems to stumble ever so slightly. It still rips, but I feel it could be better. Where is this number for FMF? Is it in their advertisement in the mags.?

 

THE STOCK CARBURETOR IS NOT A KEIHIN, IT IS A MIKUNI! I GUARANTEE IT! LT5001987 has an aftermarket carb on his ride which is why he states he has a Keihin. I also have an aftermarket Keihin on my Quadzilla but mine is a 39mm PWK. This is why neither of us can give you jetting suggestions that will work for your carb. All three are totally different set-ups.

As far as FMF is concerned, I have never delt with them. You will have to research that yourself. You can probably use an engine like "askjeeves" and find it right away. Otherwise, like you said, the atv and motorcycle magazines may have a phone number.

 

Oops, my bad. I meant Mikuni when I typed Keihin. I was looking at a Keihin jetting chart at the same time I was writing this. A Mikuni TM38SS. I will look for FMFs number and see what they can tell me. Generally speaking, if you go to a aftermarket pipe would you go up or down in jet size? I think I'm running a 400 main, but I cannot remember. I'll take it off tomorrow and see.