Just lately, while plowing snow with the atv, it started to run rough (backfire, etc.) until I would put the choke on... sometimes the choke would have to be all the way on and other times just partially on... yet at other times it would run rough (without the choke being on) until the engine warmed up, then it would run good. As of today it won't run (except idling) unless the choke is most of the way on, even when the engine is warm. Any ideas out there? Thanks.

HI Phil,

it is not unusual to hear of this when folks are using their ATVs in the snow...

The winter air, depending on the temperature, is more dense than warmer air. So you may find that you need to run for a while with the choke on, to help limit the amount of air going in with the fuel.

Then, once the engine "warms up" and is producing heat, some of that air is drawn in to the carb, which makes the problem "go away".

There is always the chance that the plug could need to be changed to different heat range, for winter driving conditions. I would recommend checking with a local shop and see what they suggest, since they are more familiar with the local weather conditions.

You could also turn the fuel mixture screw in about a 1/4 to 1/2 of a turn, and that might save you from having to use the choke, just remember to change it back when the weather warms up, or you will find yourself fouling plugs, due to the over rich mixture.

Hope this helps, do you at least get to play in the snow after the plowing is done? 12" of snow and a set of paddle tires makes for a great afternoon!

Ride Safe. Ride Legal. Ride Again... Curtis