It did it sometimes before I did mods but now it seems to do it more. What do you think is causeing this. I know my front choke spring is sticking and I plan on replacing it tommorrow could this be the problem. My plugs look good when the choke isn't sticking so I think I got it dailed in right

 

Too rich fuel / air mixture.
It would appear you may have already determined your problem (choke sticking)

 

Thanks not2old I though so but I figured I ask. I plan on working on it tommorrow. I have to also take the driven clutch back off when I first got the machine I had the dealer adjust the defection (big mistake) and the forgot to put one of the roller pins back in the clucth. I noticed it when I took out a shim. Got to love dealers.

 

bluerhino how many turns are you supposed to set the air mixture screws. when you turn them all the in how many turns out are they supposed to be

 

I started at 3 and 3.5 and fine tuned it. I carried a screwdrive with me and kept turning them a very very very little until it seemed to run great.

 

Too much raw gas in the exhaust system ...... ???

 

If you have an exhaust leak it WILL cause one to backfire.....Muffler mod?

 

BlueRhino,
From my experience your machine is lean time to up the jets please use Keihins jets they are more friendly to your quad. A good combo is 142 & 145 some have washers behind the needles but not necessary. This should help get rid of the bang coming from your quad. It is normal to get some back fire as a result of modding your intake and exhaust.

The best way to adjust your air screws is to start from the front run the motor till it is warm. On the front carb turn air screw in till the motor starts to sputter/cough take note of how far the screw is out from bottom eg. 2 turns from bottom. Turn out the air screw untill the motor wants to run faster than idle take note of position from bottom eg. 3 3/4 turns. Now take a position half in between the two and you will have an approximation of where the air screws should be eg. 2 7/8 from bottoming out or three turns. From this position you have the option of turning in or out to maximum effect I suggest turning the screw 1/4 turn in or out take the quad for a ride. If it lags some what on initial stomp turn in the air screw on both carbs. Just fine 1/4 turns untill you have it running where it should be you don't have to turn the screws very much say up to 3/4 turn either way after you have it set initialy. Hope this helps.

 

If your quad is backfiring out the exhaust, it is rich. Out the carbs, it is lean. Also check and make sure you have no exhaust leaks, someone mentioned that. good luck.

 

Alltoys I already have the 142 145 combo in. I put the new choke springs in today but didn't have time to put all the plastic on. I am going to run it tommorrow and see how it runs. Thats how I got my starting point on the air screws and I have been fine tuning them in but with the front choke sticking it was not right I am going to start over and adjust them now that everything is in working order. I took my time and did a lot of test runs if it wasn't right I would move the air screws a very very little and then try in again