Flat top piston adjustment?

[mcc1961]

How do you adjust a flat top piston to the right length?

[BenjiHunter]

When the piston touches the valve and the handle is about 1 inch from fully closed, you're good.

[Matt15]

If you have to cock your gun before you pump do not cock it to adjust your piston. Doing that will allow the air to escape and you can feel the FT piston and valve make contract.  Good luck.

[BillK]

Don't put the Oring on the piston until you have adjusted it.

[mcc1961]

Thanks for all the help.

[D14Jeff]

when i got mine from AC Customs this is the page he sent me to install it ....... pretty much as others said here .

http://accustomparts.blogspot.com/2013/05/installing-flat-top-piston-and-valve.html

AC makes great stuff , is very reasonably priced and shipped fast . 

[rsterne]

I think you will find that 1" from closing with the gun fired is pretty tight, and will put a lot of strain on the linkage and pivot pin and tend to wear things out pretty fast.... I pump the gun once, dry fire it to release the pressure (no pellet) and then check to see where you can feel resistance on the handle, without opening it enough to allow more air to enter.... I like to feel the resistance start 1/2" to 3/4" from closed at the end of the handle.... Less than 1/2" and the pump will tend to fall open after you fire the gun.... More than 3/4" and you are putting a lot of load (and wear) on things.... Of course with no O-ring you won't have to fire the gun to relieve the pressure between the piston and valve, that's a good tip....

Bob