Author Topic: Sam Yang - Seneca 909s o-ring sizes  (Read 302 times)


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Sam Yang - Seneca 909s o-ring sizes
« on: May 20, 2020, 10:10:42 AM »
Yet another Korean Airgun in need of o-rings. Sam Yang - Seneca 909s o-ring sizes are difficult to find.

I have sent an email To PyramydAir asking for a list of sizes but they are taking their time.

I did get a response on GTA from Matthew:

BUNA-N  70 D metric orings
one 21 x 3 and two 14 x 2.5   
tube end plug:
one 17 x 3 main valve
one 8 x 1.5 manometer
two 5.8 x 1.9 transfer port
one 6.8 x 1.9 barrel adapter ( a bit too thick but works if careful)
Breech loading cover SAE 014

It is also helpful to search for other Sam Yang rifles of the same family to track down sizes. This includes the Sam Yang - Seneca Recluse, 909, 909s, Wing Shot, Double Shot, and Dragon Claw. Some rifles have single or double air reservoirs which will most likely change O-ring sizes.

I’m going to attempt to put together a table of i-rings for these air rifles so the next person can easily order a set of o-rings and get their rifles back in order.

All of the Sam Yangs have fill port check valve problems here and there. On some rifles like my Sumatra, the check valve is made of brass and has a soft plastic sealing washer. On my 909s it has a plastic fluted barrel shaped check valve. Both of my Sam Yangs have had these check valves fail. Cleaning may help, as might polishing the check valve seat, and/or reversing the seal on the brass check valve or reversing the plastic fluted check valve.

Will Piatt says he makes his own from some magic plastic material, and I believe has installed a retaining/ tensioning spring. Sometimes pointing the barrel down will help the check valve seat itself.  I just had ok luck by filling the rifle, leaving it tethered, and pointing the barrel down and dry firing. That seemed to work (knock on wood.)

I have had a Eun Jin (Sam Yang, Seneca) Sumatra fail with a broken in two pieces valve poppet. Will Piatt came to the rescue for this and sent me one of his poppets. So far so good. I will order a back up of a 909s poppet from Pyramyd as Will suggested. (I think I wore out my welcome).

Will add to this thread as I discover o-ring sizes and find sources such as the o-ring store.

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