MP5 motor help
 

Well, I recently acquired a used CA MP5, everything works fine and looks alright, but my problem is rather strange. As soon as I get everything in place, put the motor, connect the battery, etc; I get next to nothing from the gun!

I know the motor is working because I can hear it...
I know the shims are just right because I can mount the motor and the everything works right. (Yes, I was testing it outside of the pistol grip)


So, I ask you, the wise members of ASC, what can I do?
My mechbox is a near mint Systema M120 with a CA high torque motor (Obviously a long type. :P)

what size is your battery?

Running a motor outside a gun is way different than assembled. When disassembled it doesn't have a load.

Battery is an 8.4v 1800mah, I took out the m120 and threw in a Modify s100 to test it.

What I meant by testing it outside was to see if it works, THEN I put the motor into the mechbox WITHOUT putting it into the pistol grip.

When I push it into the mechbox (sans grip), it works fine; when I assemble the grip, it doesn't mesh right...

Looks like I'm missing this piece, so I ordered one...This

Yes you absolutly need this piece !!

But I've found that screwing too tight the screws will jam the gearbox. If you can't move the airnozzle almost freely you should check for your screws.

Hope it helps !

You definitely need a motor plate for the motor gear to engage the gears correctly!

Your shim job may have been too tight. Re-assemble the mechbox without the piston and spring and use your finger to spin to the sector gear. It should move without much effort, if it doesn't move or it requires a lot of force to move, you have shimmed it too much, remember when you screw the mech box together it tightens it up quite a bit. Also on the motor plate, if you tighten the screw that pushes the motor plate in too much, it can also cause the same problem.

Gears move fine, the former owner got the shimming checked out by his gun doc; it HAS to be the motor plate, which is essential (As Styrak pointed out, heh heh.) I didn't realize that it didn't come with the gun, oh well, I paid $400 for the gun. :D

I'm supposed to be getting my stuff tomorrow so I'll put it in and see if everything works, if not; I'll be back.