[ronin49v]

upgrading a TM mechbox, because it would stop shooting after a few shots.

Got new:
-Trigger assembly (classic army front wired) I thought this was the problem
-systema cylinder head and nozzle
-silent piston head ( element extra part )
-new G&P gears swapped with A&E generic gears ( the gearbox didn't work with these either.)
- New 6mm bearing bushings
- external fire selector plate
- bearing spring guide

Stock:
-Cylinder
-Piston
-reverse gear
-tappet plate

I've opened and re-shimmed this @#%^ gearbox at least 8 times now with the same result. shoots a few times and then stops working like the gears are jammed.
I checked the shimming over and over and doesn't seem to be the problem.
the trigger assembly is new and I tested the connections work with a motor before closing the gearbox and works perfectly everytime i pull the trigger.
It stops working after I put motor in handle and fire it a couple of times. DAMN driving me crazy, any ideas anyone? Help?

The only thing I haven't replaced is the tappet plate and I'm not sure if its stock, looks kinda flexible to me but hey I didn't have an extra one to swap and test.

any experts out there, any suggestions will be welcome. I've opened lots of gearboxes and re-shimmed upgraded before with no problems, this one's got me totally stumped

stumped and pissed
roger