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What's the best way to shoot fire out of the back of your motorcycle? Answered

I'm going to be building a system to where I can shoot fire out of the back of my motorcycle. I do a few stunts and things and I think a flaming wheelie would end a show pretty well. So what'd be the best (and safest, I don't want it to explode if I lay the bike over) way to do this? Thanks in advance!


You might want to expand your exhaust system a bit.  The easiest way is to switch off, let the engine pump raw fuel (gas+air) through to fill it up, and then switch on again.  Do a modified kill switch, as in momentary off.  Be sure your exhaust system is solid.  We used to do this with our cars and that length of pipe made quite a bang.  I had a '66 Plymouth Valiant and saw flames shoot out from under  because the joints couldn't hold it.

The momentary-off ignition switch allows the tubes to fill with vapor that would normally be burned in the combustion chamber.  The engine pumps it through.  Release the button and the next exhaust stroke lights it all up.

You'd probably want to use something like kerosene, as it's less hazardous to be playing with than gasoline. If you injected this into a hot exhaust you'd get a cloud of flammable white smoke out the exhaust, which would probably not auto-ignite (but might) - so some kind of big-fat spark ignition or mini-blowlamp would be needed. Gasoline would burn much more easily but would be mich more dangerous.
It's similar to what this guy is doing but he's using a different engine and not getting it to burn much of the time...


Actually if the bike runs a little rich anyway the exhaust gases can easily be ignited by a spark plug... Granted it may be safer and easier to use a self contained system, separate from the exhaust and engine... I imagine a combination of an atomising nozzle and a good spark in the right chamber would be a simple way to make a nice blast of fire, if it only needs to work once per show, the system could be extremely simple and wouldn't necessitate carrying lots of fuel for it.

Best wishes for it!
And on a related note, we saw a small motorcycle stunt show (as part of an event) today. My sister was disappointed by their limited repertoire of wheelies, stoppies, use of 1 ramp, and going through fire.
On the fact that some of them were already a bit injured after previous performances: "They must be rubbish if they get injured doing poxy-stunts." She likes to be derisory about things...

Also when my mates bike started being smoky and losing power and then failing altogether: he discovered that he'd only got one quarter of a piston-ring left. I'm amazed it went as long as it did.


We had a Mitsubishi Colt that broke the piston rings and just never held oil, but ran great for years...