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gun problems

Posted: Mon Aug 23, 2010 11:09 pm
by evallia
Alright my big gun ain't working right now its 5' 2" barrel and 2' 4 " chamber and it only shoots a potato another wo20 yards I'm using rightguard for fuel any suggestions?

Posted: Mon Aug 23, 2010 11:26 pm
by clemsonguy1125
Was the potato a good fit, how much fuel did you spray in, I'm assuming it doesn't have a fan. Air out the chamber and try for a 2 second burst of fuel.

Posted: Tue Aug 24, 2010 12:09 am
by hi
Just got to get the fuel mixture right. A lot of people think more is better, and that certainly isn't true in the case of spud guns.

Posted: Tue Aug 24, 2010 10:24 am
by Ragnarok
Ninety-nine times out of a hundred, when someone comes to us with this problem, the problem is exactly as the two people above have said.

There is an optimum fuel mix - too little or too much fuel will limit power. And given the tendency to think "more fuel = more power", usually the problem is the latter. Try less fuel and see if it works better.

Also, do make sure you let the burnt gases vent out of the chamber between shots. You need fresh air in the chamber. I'm sure you know the fire triangle with Fuel, Heat and Oxygen? The fuel is your Right Guard, the heat comes from the spark/whatever ignition you're using, and the oxygen has to come from fresh air. If you haven't got enough of any one of these things, then it just won't work.

Posted: Tue Aug 24, 2010 1:19 pm
by SpudBlaster15
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Posted: Wed Aug 25, 2010 6:49 pm
by jimmy101
Easy enough to definitively tell the difference between a fuel ratio problem and a fueling mixing problem.

Air out the chamber.
Load a spud (or whatever).
Fuel as you normally do.
Let the gun sit for a half hour or so. Invert it a couple times during the wait.
Fire.

If the performance goes way up then you definitely have a mixing problem.
If the performance is about the same then your fuel mixture is off (probably too rich).

Posted: Wed Aug 25, 2010 11:43 pm
by bighead33
maybe your using the wrong right guard. be sure your propellant is flammable.