SKS won't cycle.

**Dr_Scholl** · 08-10-2010, 06:37 PM

My dad and brother in law took his new Yugo 59/66 out last week and it just won't cycle. He had to manually work the bolt every time he shot it. It looks almost new and hasn't been shot much by the previous owner.

What do you guys think, gas leak?

**AK-J** · 08-10-2010, 06:43 PM

Does it have the grenade launcher? You might want to check the gas settings, if it does.

**awp101** · 08-10-2010, 06:46 PM

Originally Posted by AK-J

Does it have the grenade launcher? You might want to check the gas settings, if it does.

+1

What ammo was he using? I found out Portuguese won't cycle reliably. To be exact, the rim is too small...

**Dr_Scholl** · 08-10-2010, 06:52 PM

Originally Posted by awp101

+1

What ammo was he using? I found out Portuguese won't cycle reliably. To be exact, the rim is too small...

122 grain Wolf.

**O.S.O.K.** · 08-10-2010, 06:54 PM

If it wasn't completely dissasembled and all of the cosmoline removed, that alone in the tappet channel would cause this.

And yes, the gas port switch needs to be open in order to allow it to cycle.

**Broondog** · 08-10-2010, 07:19 PM

yep, sounds like the gas valve is either not switched right or is clogged/bad. the correct position for the valve to be in is flipped to the right in the notch.

if you need to pull the valve or replace it you can read about it here.
http://www.surplusrifle.com/reviews2...alve/index.asp

**Krupski** · 08-10-2010, 09:07 PM

Originally Posted by Dr_Scholl

My dad and brother in law took his new Yugo 59/66 out last week and it just won't cycle. He had to manually work the bolt every time he shot it. It looks almost new and hasn't been shot much by the previous owner.

What do you guys think, gas leak?

There is a gas port switch on the gas block. It the switch in the "open" position? If the little button is vertical, the gas port is closed. If it's about 45 degrees to the right, it's open.

To move it, push down on the button, then slide it to the position you want.

(edit to add): oops I did it again... posted before I read them all. Ugh.

**Dr_Scholl** · 08-10-2010, 09:19 PM

Originally Posted by Krupski

There is a gas port switch on the gas block. It the switch in the "open" position? If the little button is vertical, the gas port is closed. If it's about 45 degrees to the right, it's open.

To move it, push down on the button, then slide it to the position you want.

(edit to add): oops I did it again... posted before I read them all. Ugh.

Yep the gas port's closed. Now I can't get the damn thing to move.

**Krupski** · 08-10-2010, 09:26 PM

Originally Posted by Dr_Scholl

Yep the gas port's closed. Now I can't get the damn thing to move.

Mine was like that too. What I did was take a propane torch, CAREFULLY warm up the area (don't leave the flame in one spot, keep it moving) and only heat it until it's "very uncomfortable to touch"... no more.

Be SURE it's not too hot and BE SURE that the torch is turned off and moved away from the area, then........

.......apply some penetrating oil to the valve and let it sit overnight.

I suggest taking it all apart. Remove the gas tube and piston. Then push the button down, slide it to vertical (off position) and slide it backwards towards the large hole.

The button and it's spring will come out, then remove the little "drum" part of the valve.

Clean all the carbon off of the valve and out of it's gas hole. A wire wheel does a great job.

Also clean out the gas block where the valve goes into.

Finally, reassemble it and do NOT use any oil or grease. If you insist on lube, use graphite powder. Oil will carbon up and jam the valve again.

It should move and work freely once it's cleaned up.

**btcave** · 08-10-2010, 09:57 PM

I have a gas tube that was out of round where it mated up to the gas port. It leaked gas there. I bought a replacement part from Tapco. Good as new.

It tapers back from the bottom to the top.

**Krupski** · 08-10-2010, 11:20 PM

Originally Posted by btcave

I have a gas tube that was out of round where it mated up to the gas port. It leaked gas there. I bought a replacement part from Tapco. Good as new.

It tapers back from the bottom to the top.

It looks just like mine (click pic for supersize)

**btcave** · 08-11-2010, 12:06 AM

I just checked my other 4 Yugos and they had the taper too. Weird. I suspected the leak so my friend Paul put some masking tape over it and it blew through it IIRC. This was 4 years ago. Replaced the part and problem solved. Maybe it leaked elsewhere along the gas tube also?

**Krupski** · 08-11-2010, 12:32 AM

Originally Posted by btcave

I just checked my other 4 Yugos and they had the taper too. Weird. I suspected the leak so my friend Paul put some masking tape over it and it blew through it IIRC. This was 4 years ago. Replaced the part and problem solved. Maybe it leaked elsewhere along the gas tube also?

My Yugo SKS gas tube fits a little loosely... and carbon soot builds up on top of the barrel near the joint between the tube and the gas chamber. The rifle still works fine though. The system doesn't need to be air-tight to work.

**Partisan1983** · 08-11-2010, 09:19 AM

I had to buy a Tapco replacement tube for my Yugo SKS.

Some monkey had stamped it with the import mark...which of course dented it in.

**videodon** · 08-11-2010, 11:38 AM

...yup, gas-related.

**deth502** · 08-11-2010, 03:03 PM

Originally Posted by Dr_Scholl

Yep the gas port's closed. Now I can't get the damn thing to move.

damn, i was with osok thinking cosmoline on the op rod.

but its not to late to be kinda right, id bet that cosmoline is causing the lever to stick. the application of some heat, as krup suggested, should free it right up.