Air Arms Owners Club

I bought a second hand tx200hc a few months ago, when I stripped it appeared to have a V-Mach kit fitted, it was only running about 9.5ft/lb but was smooth so I went with it.
Then when I chrono'd it again the other night it had dropped to just under 8.5ft/lb, so I stripped it down again to investigate.
I took the piston seal off & I'm not sure what it is.

I haven't seen one like that before,it could be a shed tuner? DIY

Have you checked the piston seal for splits,hence the drop in power.
If no splits stick a preload washer over the guide rod and into the piston.

Regards

Davy

That looks quite a professional conversion in order to fit a 25mm Weihrauch seal and shorten the stroke a little.




All the best Mick

from the photos, it looks as if someone has turned the original piston down on a lathe, and then drilled/tapped the new seal dovetail on. the photos are a little close. the first one head on to the piston face appears to have a countersunk screw.

Looks like a factory dovetail beneath that washer that holds on the HW style seal. Someone drilled and tapped the center of the latch rod to hold the washer on. Very simple way of doing this and the old style seal could still be used if the washer is removed and a screw put in the hole and cut off flush. Then again, everyone swears that the HW style seal is superior.

Update I have removed the screw and washer & filled the hole with Chemical Metal. Put an AA seal on & had 12.46 ft/lb, so collapsed a coil on the spring & added a pre-load washer & now have 10.83 ft/lb.