Anyone have any problems with the KWA MP9?
 

So I've had my mp9 for a while now, but for some reason it's started to act up and jam on me. It almost looks like the bolt doesn't fully cycle back and will leave a gap. Although the cylinder looks like its resetted its just the bolt thats not cycled. ANyone got any advice?

This usually happens when a BB gets inside the gun and blocks the movement of the loading nozzle. It's unfortunately a common problem with this gun.

damn, that's crappy. Any way to remedy it? whenever i looked to see and pulled back the bolt there was no BB in the chamber though.

Remove the upper, and see if a BB or something else falls out.

I tried that and nothing came out. I also tried making the disconnector spring looser which did help close the gap a bit but it still has problems. Maybe the actual recoil spring isn't strong enough?

mp9
 

There are two long but smaller diameter springs that run along the inside edge of the nozzle to the body (I can't remember their function) but they do at times get completely destroyed and this could be the cause of your problem

mp9
 

There are two long but smaller diameter springs that run along the inside edge of the nozzle to the body (I can't remember their function) but they do at times get completely destroyed and this could be the cause of your problem.

Look at the manual and the exploded parts diagram. This will give you a better understanding of what could be going wrong.

Bring it into Blackblitz and we can take a quick look at it. Could be something simple, could need to be submitted for tech work.

I just got it back from Blitz, they said that they couldn't figure it out. I'm thinking of ordering a new bolt assembly like the low powered one and see if that might help.

Check the nozzle spring, from what you described it looks like nozzle spring are either worn out or they snapped off

There is a short but heavy spring that pulls the bolt back.
It's known to be too heavy and prevent the bolt from fully closing up.

Get it to jam, remove the upper receiver (plastic) then nudge the bolt forward a bit. If it fires, it's that spring.
Cheap fix is to jam a flat screw driver in the spring and twist to stretch it a bit.

If I remember correctly it's part number 162 on the exploded diagram. It's the sear disconnector spring.

I think that I've tried this is the spring is the one that I'm thinking of, i found that it did in fact help a bit and close the gap but the gun would still have one and wouldn't fully cycle again.

I also think that this is the problem, but I just cant seem to get the little pins out at the rear of the bolt assembly to get access to the springs they are too tight for me to get out.