What causes a loud bang like a gun when kicking the 5 hundie over ?

[kiwikx500]

I had not had the beast out for a while and kicked it over it started after half a dozen kicks and then died after 20 seconds,got it going again rode around back lawn and died when i slowed down to turn sharp left it for a while changed plugs and when i kicked over the 5 hundie it let out a bang like a backfire,it happened once before out on a trail.Im running 98 octane at 32 to 1.
Is it just a build up of flooded petrol etc that causes the backfire ?

On a brighter note if anyone would like to go to www.racetothesky.com and click on the full results link it can be seen that the 5 hundie unleashed alot of devastation in one of our classic races here in New Zealand,it might also be of interest to any one that wants to come to New Zealand and enter Race To The sky.

[hughes]

Mine back fires some times. I think it is just a fuel mixture thing. Mine runs great. My will back fire during a cold start. If mine gives a little back fire during a cold start it will start the next kick.

[01KX5WOODSRIDER]

Mine has done that too. I think its unburned fuel in the exhaust
pipe. It gets the attention of anyone behind you.

[Polar-Bus]

Those are commonly known in the 2 stroke riding communitity as "exhaust cannons". They are especially cool when you have a pesky dog sniffing your bike, and a "cannon" booms off.