2013 Polaris Pro 800

[SledderShawn]

Ive got a 13 polaris pro 800. The sled had 400km on it and i put a stage 3 kit on it. Upgraded head, exhaust, different cluthing and a power programmer. Once in a while after riding the sled itll back fire when i start it, very loudly. Sounds like a shot gun going off. Also when it sits for a few weeks it fouls the pto spark plug. Same plug every time, change the plug and it runs great. Any ideas whats going on? Ive only put 200km on it.
I didnt do the kit myself, had a sled shop do it

 

[JustinMan43]

does the programmer add a lot to sled by itself? or is it even possible to run the programmer on a stock sled? Im super uneducated on them

 

[JMCX]

I've heard many sleds over the years backfire right after shutting off but not starting. Some will lose oil from the injection tank into the crankcase while sitting, this could be your plug fouling. I tore my 13 down recently to put in a fix kit and one side of the case had about a cup of oil. This was after sitting for almost a year. Does it smoke really bad after sitting?

 

[SledderShawn]

yeah it smokes like a bastard when I start it after it sits for a while