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my mini won't fire

Posted: Sun Apr 15, 2007 9:37 pm
by JDP12
K I built my mini today, loaded it up, but it wouldn't fire!!!!!!!!!!1 :(

I have several reasons why it might not be firing

1) My chamber is 10 cubic inches, which seems pretty big

2) I may be putting too much butane in, my dad thought that I could never overfuel it. How do I measure how much butane to put in when it comes out as a gas??

3) The spark is SUPER SMALL, the two pin-points are like 1/4" apart, and the spark is even then really small, could it just be too small to ignite the fuel??

Okay does anyone have input, and any other reasons???

Thanks guys (and girls)

Posted: Sun Apr 15, 2007 9:41 pm
by spudthug
maybe u did over fuel because if ur using a direct squirt of butane to the chamber it sometimes comes out fast.. try putting it in in little squrts...the gap should be fine for a mini some of mine are smaler... i really never had any luck from pins...if ur using push pins u may want to get some copper nails... i have had the best from copper nails....

Posted: Mon Apr 16, 2007 10:14 am
by JDP12
K. How would you set up a butane injection system?? I'm setting one up, but I am just wondering, when you ignite it, won't the combustion go into the butane tank part and possibly melt it??

Posted: Mon Apr 16, 2007 12:03 pm
by jackssmirkingrevenge
with small chambers, it's really important to get the right fuel mix.

I suggest you use a syringe coupled with a lighter refill can:

Image

works perfectly with my small volume cartridges, just fill the syringe to 4% of the total chamber volume and squirt it into the chamber.

Posted: Mon Apr 16, 2007 4:41 pm
by JDP12
but wont it come out as a gas?? Or not because it is not coming in contact with air??

EDIT: To find that four percent do you calculate the volume of the syringe or do you somehow convert the cubic inches of the chamber to milliliters or whatever syringes are measured in??

Posted: Mon Apr 16, 2007 4:54 pm
by jackssmirkingrevenge
You fill the syringe as per the photo with the can upright, the gas will push the plunger out and you stop filling when it reaches the desired volume. If you squirt it directly into the chamber then plug it quicikly, no gas will be lost.

Your 10 cubic inch chamber is about 165mL, so 4% of that would be about 6.5mL, and that's the amount of butane you need in your chamber.

Posted: Mon Apr 16, 2007 5:52 pm
by JDP12
aaaaah okay thanks a lot jackssmirkingrevenge, I'll try that and let you know if it worked or not. How should I prevent the butane from flowing out of the syringe before I am ready to inject it? Sorry, I know it probably seems like a stupid question, my mind just isn't rolling the gears right about now.

Posted: Mon Apr 16, 2007 5:59 pm
by jackssmirkingrevenge
Don't worry, it won't flow out. Do a little experiment, fill the syringe with butane and leave it for 5 minutes. Then squirt it into a lighter. Whether you do it immediately or after a few minutes, you'll get the same size of flame.

Posted: Mon Apr 16, 2007 6:01 pm
by JDP12
k thanks jackssmirkingrevenge, I appreciate the help.......now to convince my dad that less fuel is better in this situation...

Posted: Mon Apr 16, 2007 6:13 pm
by jackssmirkingrevenge
You can show him this to prove what 4% butane in a small chamber will do:

[youtube][/youtube]

Don't forget to vent the chamber properly with a blast of compressed air after each shot/misfire, to get rid of exhaust gasses and or unburned butane.

Posted: Mon Apr 16, 2007 6:19 pm
by JDP12
holy crap, that's pretty powerful...K I went and tried to inject some butane into a syringe, but the plunger did not move... I am just using the tank from my lighter, it has a valve thingy that when you push it let's the butane out...but the gas did not move the plunger....is the pressure just not great enough in one of those?? I did just put some butane into the syringe though, and you're right it does not come out, I tested it with a match and almost burned my hand :oops: ..But do you have any theories on that??Could that butane tank from the lighter simply not have enough pressure?? That seems to be it...Where can I buy one of those butane cans?

Posted: Mon Apr 16, 2007 6:28 pm
by iPaintball
You can buy thaem at wal-mart.

Posted: Mon Apr 16, 2007 6:29 pm
by JDP12
Is that in response to getting my plunger to move in the syringe or just what fuel to use Da Pneu Kid??????

Posted: Mon Apr 16, 2007 6:45 pm
by gotbass7
your using to much fuel and you probably have a bad mix. shake it and blow on it. this is probably already said but just in case...

Posted: Mon Apr 16, 2007 7:30 pm
by iPaintball
You asked where you could buy a butane refill can, so I told you. As for your plunger not moving, the refill can will provide sufficient pressure to move it.