Trouble With Combustion

G_Singh · Mon Jun 27, 2005 8:33 pm

I can't seem to make my cannon burn fuel. The way i set mine up is that i welded a spark plug into the back and hooked it up to the clicking device in a BBQ lighter. Its worked about three times but after that its completley ceased working. I know for a fact that the spark plug is still making some sparks because i saw them through the barrel. I've used numerous fuels Alcohol from body deodorant, Gasoline, Butane, Propane. Everytime that it did work it was about a half hour after i put the fuel in. I just left it lying around for a while and clicked it and it went off. Could the problem be that the spark from the lighter isnt powerful enough. What do you guys recomend to set it off?

saladtossser · Tue Jun 28, 2005 6:24 am

maybe u put too much fuel in, or the lighter isnt working.
but from what u said, it does but only after a long time, so it is most likely that u have to much fuel.

spudshot · Tue Jun 28, 2005 8:30 am

its probably both, the bbq ignitor is getting weak, and since its weak the spark gap on the sparkplug is to large. i wouldnt look down the barrel to see a spark, if it does go off you're gonna have no facial hair for a while. and you have too much fuel, try going from a very small amount to a larger amount, and see when it ignites good

i suggest
Rightguard deodorant in the brown can
starting fluid (use the SMALLEST spray possible, that stuff is powerful)
propane, metered, or you can just open up a torch head and leak some propane in, but its not too easy to get it right

G_Singh · Wed Jun 29, 2005 12:10 pm

Well I tried starting fluid. It worked great a few times but after that it stop again. I thought it was probably because I might have put too much in there. So i left it alone for a while but it still didnt work. So does anyone have a flawless ignition system? because that lighter is too weak. I've even tried the ignition systems for BBQs but that dint work either. Is my spark plug crap?

iamthewalrus · Wed Jun 29, 2005 12:24 pm

i think the most reliable fuel injection there is is a metered propane injection, its very consistant and safe, plus it looks cool.

boilingleadbath · Wed Jun 29, 2005 2:02 pm

What shape, size is your chamber? You might be having trouble getting an isomolar distributation. Because you used steel for the chamber, your probably not going to get a new, large diameter one. Try a chamber fan. I regard a cannon failing to fire with a weak spark a symptom of other problems, in this case, I suspect the fuel is not mixing well.

Spark plugs have rather short sparkgaps, so there's no chance that it's not sparking.

*yes, I made the word isomolar up; iso=the same all over, molar has to do with molocules - propane & such.

iamthewalrus · Wed Jun 29, 2005 2:05 pm

ok, im officially using isomolar from now on, but to go along with lead, if u dont have a fan yet get one, you will get a much better preformance and your gun will most likely fire more because u will have a much better isomolar distrabusion, excpecialy with arsole

neilman88 · Wed Jul 06, 2005 10:00 pm

how long do bbq ignitors last?

spudshot · Thu Jul 07, 2005 4:27 am

depends, some last a few shots, others will last a few years, i've never had one quit on me yet

iamthewalrus · Thu Jul 07, 2005 4:54 am

ive been using the same sparker on my cannon and i click it so much its not funny. i just click it to watch the spark and it still goes almost everytime. ive prolly clicked it over 100X and my cannon isnt even finished. so there are good bbq lighters out there, but there are some really crapy ones too

darthtator · Thu Jul 07, 2005 1:46 pm

Ya it sounds like too much fuel and the fuel isn't being mixed well enough. I know that if you use butane that you really need a chamber fan because the butane is heavier than air. So based on where the sparker is it probobly won't fire unless its mixed. I would really recomend a fan and experimentation with fuel amounts. Hope this helps. keep it safe!

Nick