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Gun not firing...

Posted: Thu Jan 11, 2007 7:33 pm
by Obctg
i just built a new gun

the chamber is a 24"x4" PVC, with a stun gun wiht single electrodes in the middle and a 80mm chamber fan in the reare of the gun, at the bottom of the female cleanout adapter. i injected 4 seconds of propane witht he fan running and the gun did not fire. i then tried axe in differing amounts no more than 5 seconds worth, and alternated between fan on and off during fueling.

any help would be appreciated

Posted: Thu Jan 11, 2007 7:37 pm
by Bluetooth
What are you putting the propane with? With my mini with a 13" 1.5" chamber I put like 4 sec of propane with a torch head in the back and close it and you cant just spray the axe on the fan.

Posted: Thu Jan 11, 2007 8:01 pm
by garrettee
I use a stun gun too. When I first tried it I had my electrodes too far apart, I'm sure you checked that. And the other thing I could suggest to check is your air fuel mixture, I know you spoke of fiddiling wih it, maybe you should try some more. Too much or too little propellant can cause misfire. That's all I personally know to to tell you. Good luck.

Posted: Thu Jan 11, 2007 8:20 pm
by benstern
are you sure the fan is not blowing the propane out?

Posted: Thu Jan 11, 2007 8:24 pm
by Bluetooth
Thats a very good point. Iay ouldway evernay oughtthay ofay atthay...

Posted: Thu Jan 11, 2007 9:08 pm
by frankrede
enough with the pig latin loser.

Posted: Thu Jan 11, 2007 9:24 pm
by Bluetooth
Thats wasn't nice :lol: . Ok I guess I might stop... Sometimes.

Posted: Fri Jan 12, 2007 12:01 am
by frankrede
Lol, sorry I wa mad awhen I wrote that but pig latin is one of those things that set me off.

Posted: Fri Jan 12, 2007 6:26 pm
by Bluetooth
I'm changing all the Pig Latin comments to English for you (I got other complaints).

Posted: Fri Jan 12, 2007 6:39 pm
by CpTn_lAw
the people i see using combustion, use way too much fuel for their cannon...4 seconds is way too much. Try two sprays of 1/2 second. you will see the difference. i use a mini igniter. A good propane/butane - air mix could be ignited with a small spark. 4 % of gaz for 96 % of air. With 4 seconds of spraying, you get at least 10/12 % of gaz. usualy it works for most people cuz they have very hot sparks. But that doesn't solve the problem. It's like eating too much, and drinking a lot of Coca cola to disolve everything!! this isn't a solution, the real solution is, eat less....here, put less fuel and tell me if it did something....

Posted: Fri Jan 12, 2007 11:35 pm
by Obctg
are you taking in to account that my gun has a 301.3 cui chamber voulume

Posted: Sat Jan 13, 2007 6:47 am
by CpTn_lAw
Yes i am, i had a 4" wide for 25" long chamber, and i was like spraying 3 seconds, the spark was there, but very purple and not intense. i sprayed two seconds, it ignited, but in a long WOOSH and continued burning inside for a second. I sprayed one second, and woaw, a loud wave of blue flame came out. 4 percent is very few compared to 5 seconds of spraying.
If there is a spark inside your chaber, the problem is only a matter of putting too much or not enough gaz. Here, trust me, you put too much.

Posted: Sat Jan 13, 2007 3:19 pm
by Obctg
what were u using as your fuel?

Posted: Sun Jan 14, 2007 11:55 am
by garrettee
I believe three days ago I said to check the air-fuel mixture. I won't do that again, sorry for bothering you.

Posted: Sun Jan 14, 2007 1:55 pm
by Pete Zaria
@Obctg,
Try a can of starter fluid (hardware or automotive store). My cannon has a 250ci chamber and a 1/2 second spray in the middle of the chamber works fine. It doesn't take much of it at all.

Starter fluid has a good amount of power to it - it will blow apart coke bottle combustions (My friend learned that the hard way). But it's fine in PVC/ABS as far as I know. I've used it in my ABS gun a lot before I got a metered propane setup.

Peace,
Pete Zaria.