View Full Version : 9.6V and Piston

09-23-2007, 08:55 PM
I have been running the same 9.6v battery in my solid stocks in my TM M4 and my brand new M15A4 CA, and both some how have a stripped pistons, I understand there are other things that may have caused it, I saw that the timing gear was off when I opened the mech box with a good amount of teeth f'd up in a few places. Just was wondering if I might be putting to much energy through, thus causing the gears to move faster, thus possibly screwing the piston over. Just weird how both break, and a brand new piston not shot more then 2k rounds.

......It is made in Japan.... :/


09-23-2007, 09:49 PM
If you were running a stock spring (less than 300fps/.2g spring), that is feasible.

If you have an upgrade spring in there, no way that 9.6v should be the sole culprit.

Timing is essentially a myth. The system works itself out since the gears rotate "dumb" and only engage things when needed. There is basically one particular position that could hose things up, but rather rare to get everything set to do that.

Which teeth on the sector gear (gear that engages the piston) were messed up? The ones engaging the piston or the ones engaging the spur gear (gear in the middle)?

However, on your gun today, I really sounded like a BB jam in the field, followed by subsequent shots, which blocks the air from escaping and thus the piston doesn't move all the way forward. The gear hit the piston teeth as they are coming around again and gradually grind away at those piston teeth.