it is possible for the exhaust tho throw down some flames, blue flame not your typicall yellow.
It has happend to me at one time working for a hobby shop. Customers Crappy car Duratrax Street Force of CRAP had a hard time starting, i check all the standard stuff, needles, fuel clog, bad glow plug etc etc...
every thing checked out good started to tug on the Crap Starter engine pop and i didn't think much of it. I pull again Engine starts back fires, flames on the glass counter then motor stalls. I stear at the flames for a good 20 seconds trying to figure out if it's even possible. put out the blue fire and try it again. poof 2 times in a row!
tried for the thrid time and nothing i was able to tune the motor and the customer is on his way but that was the first time i saw a back fire and flame form a nitro engine.
there is always a first for every thing!!!