I have a question for anyone with some SKS knowledge...a friend purchased one for his son at the Dallas gun show and when he got it to the range it would not cycle, I brought it home and found the gas cutoff device clogged up and frozen, I cleaned it and took it out yesterday with no change, it acts like the gas system is totally inop, the piston is free and I ran a pipe cleaner through the gas port again plus checked the "ram" that pushes the bolt and it is free.

When you fire it the bolt does not move at all, also it is a Yugo 59/66.

Any advice is appreciated since I have no clue as to why this thing wants to be a single shot!

Thanks,
Jerry

Open the bolt and lock it, plug the Chamber end, use a rubber tip air nozzle on the barrel end and check it for gas (air) escaping were it should'nt be.

Thanks, I'll try that tonight!

Make sure the gas system is not "turned off", try it in the second position.  Also, check the bore and chamber for pitting.  I have a 59/66 and the chamber is so pitted the the bolt won't move on, after it is fired.

Someone who frequents the SKS Forum here on AR15.com might be able to help you.

Surplus rifle.com has you covered.

True,

The granade launcher switch may be in the wrong position. If it is, they will only shoot single shots.

Let me guess...yugo?
The gas cutoff switch is engaged.
Check out the link at surplus rifle to see the proper position for it to be in.

I've checked in both positions just to make sure, it acts the same in either position.
I'll check out the links.
Thanks

Try this :
Remove the gas piston tube from the rifle.

Now look behind where this tube sits,looking from the front
towards the bolt area.

In here is a push rod ,similar to the gas piston,but much smaller
and it isn't chromed.This is right under the rear sight leaf .

See if it's there first.If it isn't buy one.
If it is there,take off you dust cover ,and remove the bolt and bolt carrier.

Now place your gas piston against tie push rod ,and smack it with a rubber
mallet until it moves.
If it won' move,get forceful with it .
If it still won't move ,push the swiveling retaining clip up and out of the way.
Turn the rifle around.Put a steel rod through the opposite side and pound until
it comes out ,or until you think a gunsmith is required.(Best judgement here)

If the pushrod was rusted in,I'd toss it and get another,and hone out that area
and get a fresh spring for it .

I've seen this push rod rusted in before and
I've seen a few rifles that didn't even have it.

If this isn't it ,I'd ask at the SKS forum.
It's also possible your gas switch is faulty.

I had thesame problem with my Yugo..... What the problem was , the gas switch plug was corroded badly from corrosive ammo. It formed a gas leak at the switch. I made another plug and it's now cycleing fine. An untrained /  army with corrosive ammo==== rusty rifles that malfuction. WarDawg

Turns out it was the gas system, I pressurized it and it leaks like a sieve!,
thanks to "muttonhead" and all who replied.

Yugo ammo is corrosive, and the used rifles frequently suffer from its effects.

That's too bad the rifle's gas system is corroded.  Can changing the gas piston and operating rod remdy the problem.  If you can't get it repaired at a reasonable cost, Yugos are cheap enough that you can replace it.  This time make sure it either comes in cosmoline from the dealer or that you can try it out on the range.

When your friend bought the SKS at the gun show did he buy it from a dealer or was it a private sale?  It may be that the private seller used corrosive ammo and failed to clean the rifle.  I would think that the Yugoslav military would make sure their soldiers clean their rifles more than a careless owner in the US would.  I have a shooter grade SKS which functions flawlessly and have friends who also purchased SKSs at the same time from AIM Surplus and are happy with them.  I wouldn't uses corrosive ammo because I don't always clean my guns right after shooting which you Must do to avoid rust.

I called and told him about the problem, my suggestion was buy another from SOG or someone else who will replace it if it is corroded or won't function.
I have gotten some great deals at the shows but as always you have to be sure and check them out!
He hasn't replied back to my message but he will most likely just use this one for parts since it would require more to buy the parts to fix it than to get another.
Thanks