Umarex Notos not Firing

[Ltomlin]

Zeroed my Notos today outside finally ... After 5 shots it went from firing normal with authority to a "plink" sound when I pulled trigger with nothing happening. Got pellet out of breech, shut off air from Huben valve, degassed the plenum, closed bleed screw and reopened pressure from Huben to the Notos. Same thing, nothing but the sound of the trigger releasing and a "plink" sound. Cocks fine (seems to at least.) The only thing I have done recently was adjusting the trigger pull to slightly lighter.

Any thoughts? Pressure shows 4000 psi on input side, 1900 psi on output side.

Bummed it's ALWAYS worked perfectly.

 

[kahu]

I'd start with that trigger job and reverse what you did and see if that was a related incident. Make sure you're adjusting the right screw and check the other(s) that might have any influence on the trigger assy.

 

[Ltomlin]

EDIT ** The air is coming from the breech / barrel when the probe is pulled back. When it’s pushed in it stops hissing. Is that the oring on the opening to the breech? Or something else?

 

[Scotty1]

Sounds like your valve is hanging open, or broken, sorry to say…

 

[Ltomlin]

Found the issue - poppet is broken in half! Not sure what causes that, maybe all the porting I did? Now I have to search for another one on here.

 

[jarmstrong]

maple makes them

Umarex Notos / PP750, PP800, CP1, CP2, upgrade poppet valve

Upgrade exhaust / poppet valve for Artemis / SPA / Snow Peak / SMK PP750 / PP800 / CP1 / CP2 / Diana Airbug / Chaser / Bandit / Dragonfly MK2, etc.Valve body is precision machined from high quality Delrin material. Mated to polished 303 stainless steel stem.Will fix air leaking from barrel...

maplecustomproducts.com

 

[rdpjr6504]

The PP750 valve is the same. Call Wes at AIRGUNARCHERYFUN he should be able to get you one.

 

[WoodWelder]

Found the issue - poppet is broken in half! Not sure what causes that, maybe all the porting I did? Now I have to search for another one on here.

Umarex Notos / PP750, PP800, CP1, CP2, PEEK upgrade poppet valve

Upgrade PEEK exhaust / poppet valve for Artemis / SPA / Snow Peak / SMK PP750, PP800, CP1, CP2, Diana Airbug, Chaser, Bandit, etc. NOT compatible to PP700.Valve body is precision machined from high quality PEEK material. Mated to polished 303 stainless steel stem. Optimized sealing surface...

maplecustomproducts.com

 

[WoodWelder]

Found the issue - poppet is broken in half! Not sure what causes that, maybe all the porting I did? Now I have to search for another one on here.

Note 2: DO NOT fire when the cylinder is not pressurized! Both factory and upgrade valve will crack if dry fired without cylinder pressure.

 

[Ltomlin]

Note 2: DO NOT fire when the cylinder is not pressurized! Both factory and upgrade valve will crack if dry fired without cylinder pressure.

I haven't ever dry fired it without air in the cylinder.

 

[NCAirLine]

If you order from Maple Custom, I'd suggest ordering two of the PEEK valves just to have an extra on hand. I figured if I didn't, I'd break it somehow. lol

 

[Ltomlin]

If you order from Maple Custom, I'd suggest ordering two of the PEEK valves just to have an extra on hand. I figured if I didn't, I'd break it somehow. lol

Funny that’s EXACTLY what I just did! Can’t be too careful.

 

[jarmstrong]

he has delrin and peek, which do you think will seal easier,,, which do you think will last longer, I believe I got the delrin, but won't swear to it.
put in my SPA P-15 and sealed up just fine,, been a few months ago,,,

 

[Ltomlin]

I went with peek option, said it’s better under higher pressure and I’m running mine on higher side. Says it may take a few pressurized dry fire cycles to seal up. We shall see, if not I’ll order the Delrin.

 

[WoodWelder]

IMHO, either choice will be better than the OEM one?

I've put a few thousand rounds thru my original OEM unit with no issues so far.

This is my go to barn pesting unit. I luv it!

 

[NCAirLine]

The PEEK I ordered had no issues with initial sealing. Standard porting, dream valve. Very pleased overall.

 

[Ltomlin]

Got it all back together with new peek poppet today, done in less than 10 minutes, no issues back to work.