After a few weeks of sitting in the garage, I started up my 2006 Sportsman 500 (carb) and it was running fine for few minutes until I pulled on the throttle slightly to give it some gas and it backfired. Now, I try to start it, and it turns over, but it will not run. There is a slight smell of gas when I'm trying to start it up, but she just wont take. I replaced the sparkplug and that didn't make any difference. ny ideas?? Need help cuz this thing has been in the shop after every single ride and I'm sick and tired of pumping money into this brand-new-putchased machine!! Any help is much appreciated!!

 

maybe a stuck float

 

I would try and clean the carb with some Sea Foam.

If you can, take off the intake rubber at the carb and "throw" in a capful of Sea Foam as you turn it over - then let it sit for a few minutes. Then try to start it again.

My theory is that a deposit let loose and plugged the carb.

Try this a few times. If it doesn't work, you may need to take the carb off and clean it by soaking in carb cleaner or take the carb to someone that will clean it for you.

Good Luck

BTW - If you don't already, I'd recommend using Sea Foam or Sta-bil every time you put gas in the tank.

 

since it back fired i would double check the woodruff key on the flywheel. those things are there for a reason. it it shears it could have messed up your ignition timing. but a simple replacement of that woodruff key would fix it all. now the backfiring im not sure about. spark plug could be dirty and not be able to burn off all the gas in the chamber then you get a pre-detonation from the build up left overs.

 

A buddy of mine had a scrambler 500 and the carb would come apart at the rubber boot over rough bumps, maybee the backfire blew it off the boots.

 

Normally I have found when they backfire the carb is blown out of the boot to the cylinder..Is this atv carb or injected???

 

A first check should be the Throttle safety device. Since you moved the throttle, it may have someting to do with the backfire. In my Polaris experience, if the "Stuck-Open Throttle safety device" grounds the ignition while running, you'll get a backfire. And it will also prevent the engine from running.

Pry open the throttle cover, and look at the how the switch mechanism makes up (or not). The switch should appear open, but if you hold the throttle cable and release the thumb lever, the switch should make up.

This device is designed to ground the ignition with a stuck-open throttle, and the thumb lever released. Hope this helps.

Bill

 

Thanks for the posting Miniexcavator...is this something I can check myself or does need an experienced mechanic to find the float?

 

thanks Brainerdian...sounds like you have some real experience, however how do I find the rubber intake? dunno where that is...

 

Thanks eggenz...where is the woodruff key? and, I replaced the spark plug (the original was blackened) and that didn't help.