GBB problem this time
 

I am not a GBB tech by any means, I specialize in electric. So I want to help a friend with his GBB but I am out of my league. Google search and ASC search has not lead to any solution for me.

My friend has a KJW M1911 GBB. It used to shoot 30-35 shots easily on a charge of green gas/propane w/silicone oil. Now it only shoots 10-15 and there is a huge blowout of gas back around the hammer. Obviously that is where the extra gas is going.

Does anyone know why this happens? Do you know what needs to be done to fix it?

maybe needs lubrication?

+1, try it out before breaking it down...

Roger that, I will let you know the results.

dry/worn oring on the "piston head" inside the cylinder/loading nozzle? ..or worn loading nozzle?

Or cracked/broken loading nozzle.

just an FYI, if you end up needing a new piston head, because of a worn or damaged Oring, do NOT get a nineball or king arms or any other of the ventilated piston head, they are slightly thicker than the normal ones and the KJWs nozzle is a slightly different design htan TM, and it wont let the slide fully into battery,

Thanks, TNL. Looks like it is the piston head too. Chance of getting a KJW piston replacement?

I have a KJW P226 parts gun. If I took the piston from it, would it fit?

For the above posters, the gun was lubed adequately; possibly too much lube.

theres a few places that carry a TM piston head, that would serve quite well, I've got a bunch spare if you want one