I'm pretty sure I'm already registered here but my name (Siggi) and password aren't working so I've made a new account.
Anyway, on to the business.
I have an S&T PPSH-41 that has caused endless grief from day one. I bought it brand new from Zero One and had it upgraded before delivery. They fitted a high-speed motor (JBS), high-speed gears and a poly piston. The gun failed to perform correctly on the first skirmish so I sent it back. Next use it stripped a gear, sent it back. Third use it jammed within an hour, not sending it back. They've tried everything to avoid the warranty and charge for new parts, real douche-bags I'm afraid.
So, I'm doing the work myself. I've had the gearbox open a number of times now and have found the motor they fitted (short type) had a slightly longer shaft than the stock one, causing the pinion to be way too far into the bevel (like a mm of clear space BEHIND the bevel-gear), and not adjustable (no slack in there at all). So I put the stock motor back in, also found the bevel-gear needed a whole 1.1mm (!!!) of shimming to get the right angle on the bevel-gear axle (not the original gear I should add).
So, it fires ok on anSP130 spring (Gaurder, so more like an M140?). I also fitted an SHS full-metal teeth 15-tooth piston. I get a tad over 400fps from this set-up, using a 7.4v LiPo (bit slow ROF, but ok).
But I'm expecting stuff to blow up. So I've ordered a 'silent' piston-head and cylinder-head (SHS) to spare the gear-box shell, a different high-torque motor (GFC Tornado F1 High Torque Short Motor, because the shaft looks to be as short as the stock one) and a 16:1 SHS gear-set. I'm also hoping the gear-set will fit more nicely in the box and not require the crazy amount of shimming it has currently. Also ordered a 14-tooth SHS piston too.
The question, after that long-winded intro, is will that motor, piston (14-tooth) and gear-set run the SP130 ok?
TIA for any and all advice.