Benjamin 397P Phase 1

[ratbuster2240]

I found a .22 multipump to add to the .177 and .20. It's a Benjamin 342 made in around 1980 in St Louis. I had seen a few .177's (347) but held out for a .22. It's in good original condition with most of the black finish still present. The owner said he had it from new, it holds air but not for very long and it doesn't look like the valve has been opened up before, so I'm expecting lots of gunk and hardened seals.



The pump arm was creaking when pumping it up and I thought maybe the rivet has had it. It may have a lot of wear because it doesn't look like the gun has had much lubrication. I cleaned a lot of gunk out around around the rivet and let it soak in WD40, then another clean and several drops of Secret Sauce oil has made the creak go away.

[ratbuster2240]

The inlet seal is rock solid and deformed, I'll try a Sheridan inlet seal carrier with a poly seal and it should last another 40 years.

The valve stem seal is also very deformed, the gun may have been over pumped but the owner said he never did go over 8 pumps. I have a spareAS2250 valve stem but it will need slimming down to fit inside the valve spring. It's quite clean inside the cylinder and no usual hardened grease.

[--ped--]

looks to be in good nick
the bengy valve spring is for a 1/4" stem seat ,the last one 347 i did i fitted a disco stem and a sheridan spring with the same inlet seal and carrier
looks like it's had it's hammer spring badly chopped to limit it

[ratbuster2240]

Thanks Ped, the brass inlet seal carrier is one you machined, when I opened up the 397 Ilearnt from the factory they started fitting these as standard in Benji's.The as2250 stem now fits but it sits very shallow in the valve spring. My 347 and sheridan both have the disco valve.

[jirushi]

Nice 342!
And a lot of fun to bring back to life.
I still have a brass valve body for you if you want; send me a pm and I am happy to post to you foc.
I've tried to use an inlet seal carrier with "post" in the middle in a gun that had an older type inlet seal carrier without that post.
It didn't work. I think the inlet seal seat is different for both types. But perhaps you will get better results.
Sheridan and Benjamin used both types. They have exactly the same configurations.
I highly recommend Lawrie for resealing the old valve and inlet seal carrier without hole in the middle if you come to the conclusion that that is necessary at some point.
Btw I received hammer springs with power adjusters from Ped recently. Super cool. Will start to experiment with those soon!

[ratbuster2240]

Thank you Louis that is very good of you and likewise if you need anything I can check my spares box.

When Benjamin bought out Sheridan in 1977 they started using the Sheridan valve. Hopefully with my 342 being 1980 a Sheridan inlet will fit. I shall report back either way and If not I'll send Lawrie a message.

That does sound like fun having a dual shot pumper and without power restrictions where you are both shots will produce very good power.

[ratbuster2240]

I put the 342 back together and now waiting to see if it holds air.
I cleaned the stock up woth 0000 fine wire wool and beeswax furniture polish.







All internals were polished ready for new seals.