G1 Gas System Problems

flejl · March 27, 2004, 19:23

I have been working out the bugs on a G1 build and need a sanity check. I have polished the bolt carrier, bolt carrier rails, and the hammer (FSE). After this, it would run fine on a gas setting of 2 for the first five rounds, then I would start having problems with FTF's. I rechecked all of the gas system parts and found a small crack on the muzzle end of the gas tube, so I replaced it with one from another kit, still NFG. I then replaced both recoil springs (new ones from Tapco) and succesfully turned it into a single shot bolt action rifle. I then tried a mix of the new inner spring and the older outside spring and it works for 8 out of 10 rounds. For a sanity check, I compared how tight the gas tube threads into the gas block with a GG Imbel kit and and SA R1 kit I have, both are much tighter. The build already has a new gas piston (from FAC).

I have read simular post that suggested placing some teflon tape on the threads to check if the gas tube/block is leaking. Any other ideas would be appreciated.

mrbonecrusher · March 27, 2004, 19:58

Does the gas piston fall through to the bottom when you take off the spring and remove the bolt/bolt carrier? Did you put the little pin back into the gas block after you changed out the tubes? Did you screw the gas tube in as far as possible then back it out to line up the flat spot for the pin? Is there evidence of gas leakage, like carbon, on the gas tube just aft of the gas block? Have you tried changing the gas plug? Remove the front sight post and check for carbon blockage of the gas port. If you've run through this list do try the Teflon. I use the liquid from an auto parts place, cost about $4.00. If Teflon doesn't get you up and running, check the size of your gas port. You may need to open it up a bit. Do a quick search on port sizes and go from there.

flejl · March 27, 2004, 20:23

Does the gas piston fall through to the bottom when you take off the spring and remove the bolt/bolt carrier?
Yes

Did you put the little pin back into the gas block after you changed out the tubes?
Yes

Did you screw the gas tube in as far as possible then back it out to line up the flat spot for the pin?
Yes, but on my G1 I have to rotate it back about 1/4 of a turn to go back to the flat spot, on the other two kits, it os only about 1/8 of an inch.

Is there evidence of gas leakage, like carbon, on the gas tube just aft of the gas block?
Yes, carbon on the outside of tha gas tube, next to the gas block.

Have you tried changing the gas plug?
Not yet, I have have a few I can try.

Remove the front sight post and check for carbon blockage of the gas port.
No blockage, I can poke a small piece of wire into the bore with the front sight post removed.

I have thought about increasing the gas port size, but it seemed like there must be a leak. How long does the liquid teflon last?

CFDTL14 · March 27, 2004, 20:51

go ahead and swap the gas plugs, it worked on my G1, and has enabled me to
finish working on the rifles function.

gordonm1 · March 28, 2004, 09:52

try friction test on gas piston with piston in several different rotations. It might bind when it is rotated.

Also clear gas hole in barrel. It can get gunked up and can also get metal shavings from bullets passing by.

My G1 was my first rifle and it was very worn. Even a new tube and piston did not work. The new tube kept blowing out of the threads. I ended up soldering a tube in. Yours does not sound this bad.

March 27, 2004, 19:23	#1
flejl Registered FALaholic #: 10776 Join Date: Jun 2003 Location: PA Posts: 640	G1 Gas System Problems I have been working out the bugs on a G1 build and need a sanity check. I have polished the bolt carrier, bolt carrier rails, and the hammer (FSE). After this, it would run fine on a gas setting of 2 for the first five rounds, then I would start having problems with FTF's. I rechecked all of the gas system parts and found a small crack on the muzzle end of the gas tube, so I replaced it with one from another kit, still NFG. I then replaced both recoil springs (new ones from Tapco) and succesfully turned it into a single shot bolt action rifle. I then tried a mix of the new inner spring and the older outside spring and it works for 8 out of 10 rounds. For a sanity check, I compared how tight the gas tube threads into the gas block with a GG Imbel kit and and SA R1 kit I have, both are much tighter. The build already has a new gas piston (from FAC). I have read simular post that suggested placing some teflon tape on the threads to check if the gas tube/block is leaking. Any other ideas would be appreciated.

March 27, 2004, 19:58	#2
mrbonecrusher Registered FALaholic #: 6604 Join Date: Jun 2002 Location: Pocatello, Idaho Posts: 815	Does the gas piston fall through to the bottom when you take off the spring and remove the bolt/bolt carrier? Did you put the little pin back into the gas block after you changed out the tubes? Did you screw the gas tube in as far as possible then back it out to line up the flat spot for the pin? Is there evidence of gas leakage, like carbon, on the gas tube just aft of the gas block? Have you tried changing the gas plug? Remove the front sight post and check for carbon blockage of the gas port. If you've run through this list do try the Teflon. I use the liquid from an auto parts place, cost about $4.00. If Teflon doesn't get you up and running, check the size of your gas port. You may need to open it up a bit. Do a quick search on port sizes and go from there. __________________ Ships boarded, plundered and sunk by appointment only. Custom pirate attacks available.

March 27, 2004, 20:51	#4
CFDTL14 Registered FALaholic #: 8451 Join Date: Dec 2002 Location: Illinois Posts: 99	go ahead and swap the gas plugs, it worked on my G1, and has enabled me to finish working on the rifles function. __________________ Take a friend and teach them to shoot. Last edited by CFDTL14; March 28, 2004 at 06:25.

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March 27, 2004, 20:23	#3
flejl Registered FALaholic #: 10776 Join Date: Jun 2003 Location: PA Posts: 640	Does the gas piston fall through to the bottom when you take off the spring and remove the bolt/bolt carrier? Yes Did you put the little pin back into the gas block after you changed out the tubes? Yes Did you screw the gas tube in as far as possible then back it out to line up the flat spot for the pin? Yes, but on my G1 I have to rotate it back about 1/4 of a turn to go back to the flat spot, on the other two kits, it os only about 1/8 of an inch. Is there evidence of gas leakage, like carbon, on the gas tube just aft of the gas block? Yes, carbon on the outside of tha gas tube, next to the gas block. Have you tried changing the gas plug? Not yet, I have have a few I can try. Remove the front sight post and check for carbon blockage of the gas port. No blockage, I can poke a small piece of wire into the bore with the front sight post removed. I have thought about increasing the gas port size, but it seemed like there must be a leak. How long does the liquid teflon last?

March 28, 2004, 09:52	#5
gordonm1 Registered FALaholic #: 11572 Join Date: Aug 2003 Location: Yakima, WA Posts: 275	try friction test on gas piston with piston in several different rotations. It might bind when it is rotated. Also clear gas hole in barrel. It can get gunked up and can also get metal shavings from bullets passing by. My G1 was my first rifle and it was very worn. Even a new tube and piston did not work. The new tube kept blowing out of the threads. I ended up soldering a tube in. Yours does not sound this bad.