Looking for help with Star M249
 

I am looking to replace the piston and cylinder on my star m249. I am having a horrible time finding the pieces. If anyone can point me in the right direction I would appreciate it. And Wargamers does not have the right one. First place I looked


Thanks in advance

Drink beer.

Piston is just a standard AEG piston form what I recall, cylinder.............. not sure but I'd assume it's standard as well.

The cylinder has no hole and the piston is a little oddly shaped. I thought the same myself. It's killing me one cause me likey to shoot.

Cylinders with long barrels (like over 470mm or so) don't have a hole, called a port, while shorter barrels have a port on the cylinder.

How oddly shaped is the piston?

I've worked on CA M249s before, as well as upgrading one STAR M249, and I dont' recall much out of the ordinary with the STAR one (one upgrade I did was remove eveyrthing from the clear plastic mechbox and install it into a nice black metal one. )

Googling it brings up stats they say it a V2 mechbox....

Send Bartek an pm/email, he replaced the piston when I got him to redo my star m249 gearbox. I believe it was a Guarder V2 piston.

Hehe, it's not even close to being a V2 mechbox, it's an elongated rectangle shaped mechbox, same as the CA M249. Internal parts, if that's what you refer to, ok, gears, piston, cylinder, tappet, etc. are similar and we've swapped out a lot of those parts for aftermarket as well as stock TM components.

Hey sorry guys for the possible thread jack:

Used my m249 two weekends ago, shot aprox. 2000 rounds threw it and it worked awesome! Very happy with it's performance.

Went to use it this past weekend, shot aprox. 100 rounds and then the next shot the bb flew out about 10 feet. Then it worked good for another 20 rounds and then I heard a "chunk, chunk, chunk" grinding sound and no bb's came out.

My buddy and I tinkered with it later that night - keep in mind neither of us are gun doctors in any stretch of the imagination - and unjammed the gun of bb's. We then proceeded to test it out and tinker with it a bit more to try and find out what was wrong.

Here is what we were able to find out in the order that we tested and found them out in:

* With or without any bb's loaded the boxmag winds properly.
* Without bb's loaded, the gun dryfires properly - there is no "chunk, chunk" sound nor is there any grinding sound. At this point we thought that unjamming the gun had fixed the problem of the "chunk, chunk" and grinding sound. So we proceeded to test the gun with bb's.
* When loaded with bb's, the gun does not fire properly - the "chunk, chunk" sound returns and the grinding starts again.
* We took out the mechbox and inspected it from the outside. It appeared to be fine. When we hit the firing-switch (not sure what it is called) the mechbox seemed to fire properly. When we put a finger on the open end of hte mechbox and tried to fire, we got the "chunk, chunk" and grinding sound again. We are thinking that it could be the piston, hence why I posted in this thread - remember both of us are not gun doctors and this is our first time doing anything like this but we have both committed to learning as much as we can about this gun and how to fix it.

Does anybody have any ideas of what this sounds like it could be? Could we be correct with our diagnosis? Any help would be so very much appreciated.

Thanks,

DB

I'm taking a wild guess but I think it could be that the BB is preventing your piston to go back....kind of like creating a vaccum...

We were thinking the exact same thing - only we don't know enough about the mechanics of these mechboxes to know what to do to fix this problem. Hence, we were thinking it had something to do with the piston.

DB

I have no idea what the M249 looks like internally....so I can't really help but I seriously think thats the cause if you say it dry fires fine.

I was wondering if you have removed the piston and inspected the piston head?

Check the Piston head, Star 249s sometimes have the magic of falling off in your cylinder and with every shot smashing your piston head to death.

Also Check your Piston, because the back end of the star 249 piston tends to crack off and fall into your gears.

is there air coming out of the end of the nozzle? if not then there is something wrong with the piston head or piston. if its maknig a clunk clunk part, the piston teeth could be stripped and the gear is not cathing it properly making that weird noise.

Best bet is to take the piston out and compare it to a local store that sells parts.

Thats exactly what I was thinking