800 Pro back fire issue

[Roadbuilder]

I need some help, me and my buddy have 2013 Pro 800's, both with electric start. On occasion after we stop and shoot the breeze for a little while, we start backup and get a backfire. Doesn't happen often, but often enough that it's getting annoying. Mine has an SLP can and my buddies is stock. Recently had my dealer reset TPS, but that didn't make any difference. Seems like it's loaded up on fuel then ignites when starting. Is it because the electric start spins it faster or another issue, does anybody else's do this when pull starting?

If I crack the throttle when starting it it doesn't seem to do it. Any pointers on what to look for would be great.

Thanks!

 

[Reg2view]

Have you let it idle for 15-30 seconds before shutdown? Does it still backfire if you do?

 

[Roadbuilder]

Maybe a few seconds, 10-15, not 30 seconds.

 

[Scott]

A real bonafide "backfire", as in back out the intake side into the airbox...or is it popping in the exhaust?

I'm guessing the latter, which means an excess of unburnt fuel in the cyls or pipe when starting back up.

Usually it can be due to shutting the sled off at high RPM when you come to a stop.
In other words, not letting it idle down enough and idling at a "TRUE" idle.

I've got a stock 13 with a Dynoport can. I've heard mine do it on occasion, but I can't recall the exact snow/weather conditions or manner that I shut it down.

 

[Iowa_assault]

My buddy has the same problem with the same slp can...

 

[Roadbuilder]

Yes, it is coming out of the exhaust pipe. My first thought was un-burnt fuel also.

 

[Reg2view]

Backfire out the intake typically = broken reed petals, a result, not the cause. Excess fuel in a hot pipe will ignite and shoot a flame out the exhaust. Most do it when you shut the sled down, not at restart. If the exhaust temp sensor was bad, it could read a cold pipe and push more fuel in at startup, but then the sled would not run consistently, or throw a code. Let it idle just abit longer/back out of the throttle earlier before shutdown. See if it still does it. Dealer should have talked about this, too.

 

[Jaynelson]

Agreed on not letting it idle long enough before shutting down....very common on most sleds. Aftermarket cans seems to exacerbate it and/or make it louder/more noticeable.

 

['77 Rider]

I've had mine do that after a very spirited run for longer distances. I'm running a GGB mountain can on a 600.

I've also had it do that once while riding. Was flying down a trail to get home at dusk, heard the pop and a bright flash from under the belly of the sled.