Yugo SKS not cycling

[mak47]

I picked up a Yugo SKS last week from another forum member. Before he sold it to me he stated that it had issues feeding some ammo. I wasn't too worried about it, figuring it just needed a good chamber cleaning like so many SKS's do.

I took it to the range today. It doesn't have a problem feeding some ammo--it has a problem feeding ALL ammo. Out of 50 rounds only three cycled at all, and those stovepiped.

My first thought was the obvious, make sure the gas port isn't switched closed. It's not. It's in the correct position. Next thought was a worn ejector. That's not it either. The spent case doesn't even cycle the bolt. If it were the ejector it would cycle but have issues ejecting.

I took it home and cleaned the gas system, the piston seemed sticky in the tube. It would move, but only with some force--then it would fall free. I cleaned it and the gas tube, as well as the secondary piston inside the rear sight base.

I then took out a lighter and stuck the flame inside the gas block. I noticed that a lot of stuff was burning off. It stank up the room and pushed out a lot of black smoke. I'm thinking (hoping) this was caked up cosmoline melting and burning off.

The gas piston now floats freely, and I can see that the gas port is clear (at least it is now). Can anyone think of anything else I should check?

[edritchey]

Have you tried it after you got the gas piston floating freely? It sounds to me like it should be working fine now. If it is still not working you might want to let Bill Landon look at it he is a good smith and close to Harrisburg. His number is 566-2131 and his shop opens at 4:30pm weekdays. EDR

[Cbronwen16]

You may also want to check and make sure the squigly end of the recoil spring is inside the bolt carrier....i put mine together wrong once and it jammed every round. my gas piston gets somewhat sticky sometimes inside the tube but their seems to be enough oomph to knock it loose during firing.

[coat4gun]

You may also want to check that the firing pin floats freely. A sticky firing pin is not something you want in an SKS.

[mak47]

Have you tried it after you got the gas piston floating freely? It sounds to me like it should be working fine now. If it is still not working you might want to let Bill Landon look at it he is a good smith and close to Harrisburg. His number is 566-2131 and his shop opens at 4:30pm weekdays. EDR

Thanks for the tip. No, I haven't had a chance to take it back out again. Might not for a few weeks actually. I'm thinking I covered all the bases, but you never know.

[mak47]

You may also want to check that the firing pin floats freely. A sticky firing pin is not something you want in an SKS.

Already checked and cleaned the firing pin. That wouldn't make it not cycle, but you're absolutely right--a sticky firing pin is not good in an SKS.

[MDJschool]

When the rounds don't eject and instead stay in the chamber (and sometimes cause a sticky bolt), the gas valve is often thought to be a culprit when it might be pitted and worn. Also, the gas tube itself can be at fault which would be my next guess if you replace the gas valve without success.

It is always nice to have another working SKS sitting beside the one you're troubleshooting for this issue, because you can sometimes interchange the parts until you find the culprit.

You should also crosspost your issue on http://sksboards.com/ if you have not done so already.

CNCWarrior offers a same-type newly-milled replacement valve. Murray, often seen around sksboards, offers a different variant (no thumbscrew on the valve, instead mode is switched by a wrench). There may be other offerings, but I remember these two having come across them in the past.

As for a new gas tube if you need it, I unfortunately have not seen too many original issue floating around but of course tapco or whomever offers new tubes possibly with modern handguard for ~$50 (or used to).

[mak47]

When the rounds don't eject and instead stay in the chamber (and sometimes cause a sticky bolt), the gas valve is often thought to be a culprit when it might be pitted and worn. Also, the gas tube itself can be at fault which would be my next guess if you replace the gas valve without success.

It is always nice to have another working SKS sitting beside the one you're troubleshooting for this issue, because you can sometimes interchange the parts until you find the culprit.

You should also crosspost your issue on http://sksboards.com/ if you have not done so already.

CNCWarrior offers a same-type newly-milled replacement valve. Murray, often seen around sksboards, offers a different variant (no thumbscrew on the valve, instead mode is switched by a wrench). There may be other offerings, but I remember these two having come across them in the past.

As for a new gas tube if you need it, I unfortunately have not seen too many original issue floating around but of course tapco or whomever offers new tubes possibly with modern handguard for ~$50 (or used to).

I'll check out SKS boards. Thanks. I checked out the gas tube, it's fine. The adjustable port...??? That's kind of hard to tell. If everything I did doesn't work then that makes sense.

[mak47]

After checking out the SKS boards I pulled out my gas valve and sure enough, it was very pitted and wasn't forming a good seal. I ordered a stainless steel valve from Murray's Guns, swapped it out and took it to the range today.

100 rounds of varying kinds of ammo: brass, lacquered, polycoated, zinc, uncoated steel etc. It's now perfect. Goes bang every time and kicks the brass a good 10-15 feet away.

Thanks for the tip, I never would've found that valve without it!

[Mooseman]

glad to hear the new valve solved the problem. I had a similar problem and found the paper clip trick cured it without needing a new block. In case anyone else has this problem with a yugo you might want to try this first. Take off the tube and look at the block. Where the block seats in the tube there's an indent. You cut a paper clip so that it fills that ring as well as possible without overlapping and reassemble. Won't work all the time but worth passing on.