Bad Backfire

[ross932c]

Getting warmer here in Ontario, Canada, and after a hard long winter of 3 wheeling in thecool weather the 3 wheelerseemsto have been acustome to it, nowthats itswarmer it is backfireing really bad. Whenever I let off the gas all I hear is BAng, bangbanagbang....B BANG, and little flames coming out of the pipe. Whats going on here? IT did it rarely during the winter but the last couple days where it has been nice and warm it has been backfireing bad. Does backfireing hurt anything? Can I fix this?

[85_ATC_200S]

My first question is what kinda pipe you have on there? Backfiring is air being sucked back into the motor and when the xhaust stroke comes it blows it back out, its not good for your exhaust valves. My next question is are your running it with the airbox lid on or off? If your running with it on take it off and try it, if your running with it off put it back on and try it. Other than that i dunno what to tell you.

[MTS]

what dose your spark plug look like? like what colour, my best guess is that you are running too rich and the unburnt acumulated gas's in the pipe get ignited when i spark flys out, use the search button on the top of the forums and put in Jetting 185s 200s and there are TONS of threds on this..just look throgh them and you will see what you need to do

[ross932c]

The plug is black, I was thinking I was running rich, but didnt know if it would do much. The carb pins are worn so in order to get less fuel in the carb I need a carb kit. I'm just wondering why it backfires when letting off the gas. Well actually if I slowly let off the gas and sorta keep up with the revs as the slow there is no back fire. its just when I completely let go and the throttle goes to idle and the engines still reved passed that. I have the factory pipe and muffler on it, butthe muffler isrotted out on the bottem and the pipe does have a couplesmall holes in it, that is where I see the flames. But it has always been like that, and just currentlystarted backfiring. The airbox lid is on right now.

[ross932c]

But I havent changed anything execptthe temperature is getting warmer. So I'm thinking maybe the gas, because in the einter it needs more gas right? and not that it is summer its still getting all the asthat it doesnt need? Make sense?

[MTS]

in the winter, you use a larger jets/settings becuse cold air use's more gas to burn, in the summer you need less gas becuse it is warm out, and if your plug is black your are definately rich, search the fourms for jetting on thea's bikes there a zillons of threds on it

[ross932c]

My carb is already set to al low as it can go. I need a new carb kit.

[ross932c]

What set of jets should I get?

[ross932c]

Also, will burning oil makeyour plug black? Becasue it does burn oil, the rings are done in it, I'm getting new rings and a new gasket kit ordered soon.