Info needed on very early(1982 production) Theoben Sirocco end plug

[woodstock1]

The idiot who was here before me must have used vice grips!!! The fill hose from my Theoben pump will not fit the threaded fill port on the end plug. Even if it did fit, the lip on the end plug does not allow enough room to screw in. Solutions? Also there are traces of glue/cement inside the end plug. I would think that the dummy piston with oring is a straight press fit. Correct? All feed back is greatly appreciated!

https://i.imgur.com/4aG1Ime.jpg
https://i.imgur.com/mgOuClX.jpg
https://i.imgur.com/OaOx3I0.jpg
https://i.imgur.com/b4ffrCz.jpg
https://i.imgur.com/5vFBenz.jpg

[les allam]

The idiot who was here before me must have used vice grips!!! The fill hose from my Theoben pump will not fit the threaded fill port on the end plug. Even if it did fit, the lip on the end plug does not allow enough room to screw in. Solutions? Also there are traces of glue/cement inside the end plug. I would think that the dummy piston with oring is a straight press fit. Correct? All feed back is greatly appreciated!

https://i.imgur.com/4aG1Ime.jpg
https://i.imgur.com/mgOuClX.jpg
https://i.imgur.com/OaOx3I0.jpg
https://i.imgur.com/b4ffrCz.jpg
https://i.imgur.com/5vFBenz.jpg

Hi Woodstock1
I also have a very early Sirocco and it has a bespoke thread size,none of the Theoben or best fittings adapter’s would fit my gun.
Dave at Staffordshire custom guns made me an adapter to fit my gun.
The idiot as definitely made a mess of your gun.
Does the end plug have 3 retaining ex head bolts secureing it too the cylinder?.two below and one through the raised scope mount block?.if it’s a yes,the bolts are glued in position to stop any pressure leaking out.
The last bit of information was given to me by Chris Whistler,who runs Selective arms and formally Impact Airguns.
Chris recently serviced my Sirocco and it’s performing great.
It’s worth giving Dave a call regarding the adapter.
Regards
Les..

[Shed tuner]

it might clean up... the thread is something weird and BA IIRC. Not the usual schraeder type 6VD or whatever they call it.

the photos are confusing me a bit - why does it have o-rings outside on the tail of the piston ? Do you have the "dummy piston" ?

Even on my early countryman, the "spring guide" / dummy piston is one piece with the end cap, and just slides into the piston body. the piston has a couple of internal o-rings and a backer fitted to seal it, simples.

for yours to work, as you say, the dummy would need to fit inside the recess in the end block and seal... and stay put whilst being fired, which seems unlikely.

So I'm a bit confused.

[woodstock1]

Hi Les, yes 3 bolts with orings. Doesn't appear to have cement/glue. However, I have no raised scope mount block. I will contact Dave. here are some more pics. the schrader valve screws into the stainless steel bolt and that in turn screws into the end plug. My fill hose from my Theoben pump does not fit. BTW serial number 270 late 82 production
https://i.imgur.com/V3X9LzF.jpg
https://i.imgur.com/hk1g0Bf.jpg
https://i.imgur.com/AqFZPkE.jpg
https://i.imgur.com/vxfm2Ym.jpg
https://i.imgur.com/mgOuClX.jpg

[woodstock1]

Hi Shedtuner, here are pics.
https://i.imgur.com/5vFBenz.jpg
https://i.imgur.com/edsBdPe.jpg
https://i.imgur.com/rCCZRlt.jpg

[les allam]

Hi Les, yes 3 bolts with orings. Doesn't appear to have cement/glue. However, I have no raised scope mount block. I will contact Dave. here are some more pics. the schrader valve screws into the stainless steel bolt and that in turn screws into the end plug. My fill hose from my Theoben pump does not fit. BTW serial number 270 late 82 production
https://i.imgur.com/V3X9LzF.jpg
https://i.imgur.com/hk1g0Bf.jpg
https://i.imgur.com/AqFZPkE.jpg
https://i.imgur.com/vxfm2Ym.jpg
https://i.imgur.com/mgOuClX.jpg

Thanks for the photos.
I never ventured into my Sirocco,so that’s what they look like inside..
Jon (shedtuner) will have a lot more experience regarding the internal’s then me.
I think the early Theoben gas ram guns where constantly changing.
Les..
Ps
Are you in the USA?.

[woodstock1]

Outside of Toronto, Ontario

[woodstock1]

Hi Jon, according to Martin Rutterford the dummy piston has a cement/glue on the bottom of the dummy piston to hold it in place in the end plug. BTW the oring on the bottom of the dummy piston is a square oring

[Shed tuner]

Hi Jon, according to Martin Rutterford the dummy piston has a cement/glue on the bottom of the dummy piston to hold it in place in the end plug. BTW the oring on the bottom of the dummy piston is a square oring

Ahh, OK.... they must have been a very brief run like that before switching to one piece dummy/block. I'm thinking it may be a pain to clean that up so it seals properly.

Pix make sense too... i thought that was the piston, not the dummy (who's the dummy !)

[les allam]

Outside of Toronto, Ontario

Ok cheers
Not exactly just up the road then.
Your best bet regarding the adapter,ask Dave the specific size and pitch of the thread and get a local engineer shop to make you one up.Hopefully he might remember my adapter he did for me.
Les..