mM1000 weird noise

[powdercrav]

went riding today at +10C and sled ran great. but every time i shut the sled off about 3-5 seconds later theres a thumping sound coming from the exhaust. just one loud Thuuump and thats it...sounds exactly like a container of gas getting lit. some of u might know what that sounds like anyways, and ideas what this might b? or has anyone experienced this?
thanx

 

[snowmobiler]

backfire

 

[powdercrav]

ok i know about backfire when trying to start something, but backfire the motor is completely stopped and still for a few seconds? y would it b backfiring?

 

[snowmobiler]

cats do it.my new doo does it too.if you stop and let it idle a few secs before shutting it off helps

 

[UtahEdge]

cats do it.my new doo does it too.if you stop and let it idle a few secs before shutting it off helps

All 4 of the cats that I ride with do this. Like said above let it idle for a second and it will stop.

 

[knzee]

Does the sled of an advanced timing key?