SACair Forum

I noticed that the tappet plate wasn't moving back and forth to allow bbs to feed. So I took the gearbox apart, checked things out and reassembled. The tappet plate had just been replaced and did work prior to all this. The gun was test dry fired, part-way through reassembly, approximately 100 rounds, and seemed fine. The tappet plate moved, had compression, etc.

noob question,Whats Unk?

you could see the tappet plate while test firing???? you probably mean the nozzle. it attaches to the tappet plate via a groove in the front. either the nozzle, tappet plate, or tappet plate spring broke. disassemble again and look.

OPPS, yeah i ment i could see the nozzle moving back and forth. I did inspect all those parts and they seemed fine to me. Could improper shimming cause such a problem?

Shimming has nothing to do with this problem. Check to make sure the nozzle is attached to the tappet plate. Take the upper off and fire it to make sure it moves back and forth. If so, it is probably binding on the hop unit. I have only seen this twice and its a PITA

the spring for the tappet plate could be coming off, or it is binding.

i wouldnt rule out bad shimming...

[quote="snoopy"]i wouldnt rule out bad shimming...

[quote="d80"][quote="snoopy"]i wouldnt rule out bad shimming...

[quote="snoopy"]i wouldnt rule out bad shimming...[/quote]

[quote="Andrew"][quote="snoopy"]i wouldnt rule out bad shimming...[/quote]

[quote="snoopy"]probably broke your tappet if shimming on sector too tyt[/quote]

Well I took the gearbox apart and somehow the nozzle and tappet plate a staying stuck towards the back and not following through. the tappet plate and nozzle are both new systema brand. any suggestions? this is driving me NUTS!!!!

Can anyone help me out here?

First, I assume the spring is attached.

So are you saying i probably need to file down the sides (rails) of the tappet plate? (that makes sense if it keeps binding to the back)? how much should i file down or does it matter?

no he's saying look at it to see if theres any wear marks on it and if so file those parts down so they no longer rub on anything... and check that the spring is attached

File as much as is needed, where it it needed.

[quote="snoopy"][quote="Andrew"][quote="snoopy"]i wouldnt rule out bad shimming...[/quote]

No, this is on a ver 2 mechbox. Took it apart yet again and found that the "tail" of the tappet plate is getting caught on the something on the sector gear and I can't figure out how it's getting jammed up once I reassemble and fire the box (on the very first shot).