I have a 2007 Sportsman 700 Twin EFI. I am starting to have an issue we at Idle the machine sounds like it is running on 1 cylinder. Try to give it gas during this issue and it begins to back fire and cough back thru the carb. The short term fix seems to be shutting off the machine and restarting it right away and it begings to run normal . Come up on my next stop on the trail and let it Idle again and the issue starts all over again. Does anyone have any insight on what it may be or what I can do to fix my issue.

 

Maybe run some sea foam through the tank. It is a good cleaner for efi's, etc. Maybe you have some bad fuel in it? Kind of weird as it is fuel injected, so electronic controlled. My buddy's new sp800 was idling very high most of the time. Threw us through a loop, just couldn't figure it out. Shop said the throttle cable got dirt in it as it had bad seals from the factory. They replaced it all. That wouldn't be your problem though as yours is backfiring.

 

I had High Octane gas with an Octane booster. I could understand the poor running condition on bad fuel but when you shut off the machine and restart it right away it clears up the problem for a bit. Again only on Idle it seems.

 

mine does the same thing sometimes, usually after I pressure wash it, or go in some water over the floorboards, some people have said their spark plug wire rubbed on the frame, and is grounding out to the frame, also you may have a cracked spark plug boot, I di-electric greased up my boot the last time, and it has been fine for the last 150 miles or so

 

agreed that it sounds like a spark issue, and check what he menetioned for a bad cap/wire. check for corroded areas as well on wires anywear around like grounds and hot wires. side note, why are using high octang gas and as well octang booster? the bike is designed to run on 87 octang. imo

 

I run 93 octane with the octane booster to get all the horses I can out of it. Don't get me wrong. I do not miss treat the machine or run the hell out of it. The plug wires have a plastic guard around them already. When I start the machine from being cold it runs normal. When I leave it to Idle so the machine gets hot it then seems to go to one cylinder. Giving it gas it then backfires and cough back through the carb. If I shut off the machine and restart it right away it runs normal again.

 

increasing the octane rating of your fuel you use in your atv does nothing to increase power. Octane is a measurement of "resistance to combustion". What high octane fuel does is allow higher compression engines to run more spark advance with out causing detonation (spark knock or ping). Since your atv was designed with a compression ratio and certain amount of spark advance to allow use of 87 octane, using higher octane will do nothing other than waste your money. "Cetane" and not "Octane" is the measure of the explosive force of a fuel.

 

It also slow's down the burn rate wich in turn, in a low compression motor (stock) results in loss of power. Also most racing fuel is leaded and is not designed to run in todays engines in atv's and car's. Can cause valve problems. I will say that todays fuels with ethenal are terrible. The octane rating's are way off and destroy parts in the fuel system. If you must have a better fuel' try to find none ethenal fuel, usaully at a marina for boats.

 

try di-electric grease in boots on plug wires and check to see that metal clip inside boot is not broken, it will stay on plug when you pull the wire off if it is, the high octane and booster just create more heat and is a waste, Seafoam once in a while and Stabil if its gonna sit for over a month is all you need

 

i had the same problem with my 400 outlander the valves were to tight i went through every thing on it then i check the clearance on valves the intake had none and exhuast almost had none