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BSA Airsporter
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Author:  bbuffett [ Wed Jul 28, 2021 6:58 pm ]
Post subject:  BSA Airsporter

Just picked up a BSA airsporter mark 6 vintage. (1979-830)
Cleaned it up and it shot very well...put probably 200 pellets through it yesterday.
Went to cock it today and it was hard at first 2-3 inches then OK but would not fire the pellet. long story short the aluminium piston top sperated from the piston and is stuck at the top of the cylinder.
The ? leather seal is just rotted away and came out in pieces as did the little pin holding the top to the piston. I assume the 0-ring is still attached to the piston head. To be clear it was working (sliding fine) yesterday so not corroded welded in place.

I tried just banging the cylinder/barrel on a piece of wood to try to get the piston head to move down. I thought of putting a wire coat hanger wire down the muzzle end but I think that would not do the barrel or the aluminium piston head any good.
I thought of putting the tap lever back in and trying some sort of high pressure air down the barrel but read it didn't work for someone who had the same problem.

This must of happened to a lot of people as the airsporter was in production for almost 50 years and is still very popular.
I am hoping someone here has knowledge of how to solve this dilemma.

Thanks
Bernie

Author:  TCooper [ Wed Jul 28, 2021 7:46 pm ]
Post subject:  Re: BSA Airsporter

I did a bit of surfing and found many references to stuck piston heads but no good advice to remove them. I would make up a tool and try to hook it out from the back before going down the barrel. Lube up the cylinder and let it soak for a while. Make up a hook gadget. The hook end would be just a tiny but smaller than the broken cross pin. The idea is to get into the hole in the head and catch the crosspin hole and try to slide the head out through the lubed up cylinder. Maybe even a coat hanger would work but you might have to thin down the hook. If the piston head is not seized firmly then it might not take much effort to get it out, once you get a connection to it.

Author:  bbuffett [ Thu Jul 29, 2021 5:05 am ]
Post subject:  Re: BSA Airsporter

Yes I thought of the same thing last night…perhaps use two long L shaped wires and perhaps a wooden dowel between them to keep them hooked in place. The cylinder/cap is soaking in WD 40 overnight.
Thanks for the help.
If anyone has figured out a solution that has worked please chime in.

Author:  bbuffett [ Thu Jul 29, 2021 8:35 am ]
Post subject:  Re: BSA Airsporter

'Tried but didn’t work because the pin that hold the head to the piston sheared and cannot introduce a L shaped word into the hole because it is still filled with the sheared pin.
I very carefully introduced a rod through the barrel and transfer port into the cylinder abutting the piston head and tapped it but no luck.

Still looking for solutions. :idea: l

Author:  Ace [ Thu Jul 29, 2021 10:25 am ]
Post subject:  Re: BSA Airsporter

ran into this problem on many old repair jobs and managed to figure out ways to
take the piston head out but this tool would have made things a lot easier, see if you can find one of these :wink:
I know they sell 10" long ones not sure if they have something longer
Image

Author:  TCooper [ Thu Jul 29, 2021 2:26 pm ]
Post subject:  Re: BSA Airsporter

If the head is not too tight in the chamber then maybe you could wedge it out. Find a close fitting wood dowel. Wrap the end of the dowel with tape until it's a tight fit in the head. Turn the dowel and maybe even tap it into the head. Maybe it will grip enough to allow you to pull out the head. If this fails, you can try using rubbing alcohol on the tape to lubricate a very tight fit. Let the alcohol evaporate and then try to pull out the head.

A tap would grab the inside of the hole but you need the right size. Then you need to rig up something to hold onto the tap. You could glue it into a hole in a wood dowel.

If all else fails, maybe you can epoxy a rod to the bottom of the hole in the piston head. Find a rod that's a bit thinner than the hole in the piston head. Make sure the head is clean with rubbing alcohol. Then put a small blob of epoxy or superglue on the end of a metal rod and guide it into the hole. Prop it up to allow the glue to dry. This might work but it might be a job to get the glue out of the head after. Acetone will work on superglue.

Author:  ScottC555 [ Tue Aug 17, 2021 10:06 am ]
Post subject:  Re: BSA Airsporter

I had one a while ago but it had a synthetic piston head. Are you sure yours is aluminum? The reason I ask is you mentioned bits of the leather seal coming out. I thought they had a dome like synthetic seals with an o-ring instead of the standard piston seal style.

I got mine out by drilling it into pieces with a long drill bit from Princess Auto. Since I have access to a lathe I made a new one after that and used a piece of drill rod to hold it on.

I’ve seen aluminum piston heads but I thought they were aftermarket.

Another option would be use an air compressor and try to blow it out.

Author:  Leonardj [ Tue Aug 17, 2021 3:35 pm ]
Post subject:  Re: BSA Airsporter

The nylon piston heads were usually found on the earlier variants of the Airsporter.
The piston head is indeed aluminum on this particular version.

This Airsporter is presently in my workshop. I have not been doing repairs for a few years now, but decided to help out with this one because it is a repair that not everyone is equipped to do.

Whether the piston head is nylon or aluminum, the most effective method of removal is to tap the hole in the back of the piston head, and use a slide hammer to extract the piston head.
The piston head can still usually be re-used, as is the case with this Airsporter.

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