Help me Troubleshoot

[sagthegreat]

Ok I built my first Piston Valve Gun, pumped to 200 PSI and when piloted all the air burst through the back, nothing into barrel. I dont know what im doing wrong because the piston is able to move when i blow air and can move.

[sagthegreat]

Here is picture

[Zeus]

What size is the pilot? And the diameter of the piston?

[sagthegreat]

the pilot area is 1 inch long and the diameter of the piston is about .25mm less then the OD of the tube

[Zeus]

I meant the pilot valve, and the actual diameter of the piston.

[sagthegreat]

the pilot is a standed bike tire valve. outer tube is 8mm, and the piston is about 7.5 mm

[Zeus]

That's the problem, the gap around your piston is too large. Wrap some tape around it until it's a much closer fit. Them lubricate the heck out of it, and you'll be right.

[sagthegreat]

will Vaseline be a good lubricant?

[Zeus]

Yep, it won't break down the rubber. I used it before I got some decent grease.

[sagthegreat]

ok so after messing with tiny peices of tape, i got the piston so its tight enough so too much air wont leak when piloted, but loose enough for air to get past to fill the chamber.
i used a small amount of epoxy for a low pressure test tomorrow, will post a video tommorow

[Crna Legija]

id got with a bigger pilot even if it works tomorrow.

[mattyzip77]

where are the pics???? Cant help you if we cant see the pics!!!

[quark1980]

i had the same isseu with a schrader as a pilot... in the end i just made my own valve to pilot te bugger....