Jinming Gen 9 Gearbox issue

Hey Guys,
Was just wondering could please help me before I break another gearbox from stress.

I brought this upgrade kit : https://www.ebay.com.au/itm/Upgrade-Metal-Gearbox-Set-Kits-For-Jinming-Gen9-M4-Gel-Ball-Blaster-Toy-OZ/264315767304?hash=item3d8a728a08:m:m9yQZUxLAN86t81WvznIxzg

After numerous tries, swapping cyclinders and buying another 1.3 spring I can get the plunger to pull back but it will not retract any help would be appreciated because I’m close to breaking this housing too :joy::joy:

Hello @Chiich and welcome to the forum.

Which parts of that kit did you get? Or did you get all of it?
If you got all of it, what happens if you use it all except the spring and just put in the standard gen9 spring (1.1 or 1.0)


So, your piston is sort of stuck to some degree in the cylinder upon rebuild but not on the bench in bits?

What sort of damage did the previous ones suffer from?

Thanks arty ,

I got all of the kit , I have tried the standard spring and it does the same thing just pulls back the plunger but won’t retract

Can you explain that in a different way as I’m not quite sure what you mean…
Which bit of this is not happening?


See how the plunger pulls back and then retracts and shoots the gel ball mine doesn’t retract it just pulls back the last pin on the gear gets stuck on the ladder I think

Shave off the tooth that is offending. On the plunger tooth im talking about. Dont shave anything off the round gears

1 Like

Alright I’ll try that tonight and keep you posted

How many teeth on your ladder?

Have you got a nylon tappet plate to try. I have herd a few people having problems with that same metal tappet plate. My gen9 is fully modded wit a 1.4 spring and the nylon tappet plate works flawlessly.

Some teeth on the metal ones are deeper or higher than others. I had one type that used to grind and jump teeth. Took it out swapped it with a higher tooth one and she is sweet now. Not to sure on number of teeth.

This will help… Angle of engagement… Kind of what the issue is.


Can’t do better than that at the moment, on the road and running late…

1 Like

Hi @Chiich, I’m not sure you have herd about the legend @LowGuido, he has the best youtube how to’s on the internet. Check this one out of him testing an almost similar kit to what you have bought. He only used half the parts because they weren’t to compatible with the gen9.


2nd best tube tube lol

Number one… top chop chop shop on the block :+1:

I learned most of what I know about blasters from Guido :grinning:

1 Like

Wondering if you have the anti reverse latch in the right way, or you’ve missed a spring or something…