Clanktank

Some gear and shim holders for when the gearbox is in bits. Made from old bearings, brass hook stubs, and some wood offcuts. Can't have them lying around and getting mixed up. ?

It is an M5 clone but has an M4 nozzle, so the new nozzle is the exact length as the original. The cylinder head has changed so could this make a difference? I've been thinking about it over night but still have concerns. If this is common then what is it called? Whenever I search for over-spin then always diagnosed by having a double-tap, but this is just the sector gear basically hitting the piston again with no further travel, but why does it happen on both old and new gears and parts?

The gearbox was perfectly shimmed, it just clunks and isn't smooth firing, but part of that may be the piston guide needing bracing with the stock screw.

Okay, that all makes sense, but it sounds pretty awful. This also means I have other issues with air seal as the fps was jumping between 170 and 230 when first test firing, so I think the nozzle may be the wrong length.

Building a DMR from a V2 gearbox, but I have two issues: 1. When firing the gears seem to spin too far until they meet the piston again, so the resting position after a shot is the sector gear partially engaged with the piston and the tappet plate pulling the nozzle back. Has a high torque motor, SHS piston & head, SHS cylinder & head, and SHS 13:1 gears. Running 11.1v motor with 110 spring, but it's an interim spring as a bigger one will likely be needed to get to DMR power. Cutoff lever changed for a steel one, but is exactly the same shape as the original. Same happens with original gears and motor as well. Both sector gear cams only seems to move the cut-off lever a small amount, but it must be working otherwise it would go full-auto. Tappet plate is moving properly until the first shot, so the issue is not that, it must be the gears rotating too far. Picture shows what I see immediately on opening the gearbox. Ignore the bent tappet, it's just because it's now not in the guide, and the anti-reversal was temporarily taken out as well. 2. The spring guide moves out of alignment (tilts) every few shots and blocks the piston travel. It's a quick change guide and has the proper seating slots. Anyone had this issue?

Empty box for a tenner? https://www.ebay.co.uk/itm/G-G-ARMAMENT-FULL-AIRSOFT-GUN-M4-BOX-CARRY-CASE-CASING-TRAVEL-TOP-FIVE-ENG/324280256265?hash=item4b809c0709:g:5JkAAOSwwgRfTmZ1