2airishuman
Contributor
I have three Calypso IV, one with the J mechanism. Two are presently in service.
The adjustment screw is a fine adjust and will only change the IP by around 15-20 PSI over its entire travel. Coarse adjustment is with shims. Adding shims increases IP.
If you're getting 170 PSI then I would check for corrosion, unwanted shims, or other foreign material that might be keeping the mainspring from seating on the housing. The shims ordinarily used are very thin, around 0.010", and make around a 15 PSI change in IP, so it does not take much to affect IP. If there are no obvious culprits I would try a different main spring, and failing that, a new piston or housing.
Used Calypso IVs are abundant so you should have no trouble finding one for parts.
The adjustment screw is a fine adjust and will only change the IP by around 15-20 PSI over its entire travel. Coarse adjustment is with shims. Adding shims increases IP.
If you're getting 170 PSI then I would check for corrosion, unwanted shims, or other foreign material that might be keeping the mainspring from seating on the housing. The shims ordinarily used are very thin, around 0.010", and make around a 15 PSI change in IP, so it does not take much to affect IP. If there are no obvious culprits I would try a different main spring, and failing that, a new piston or housing.
Used Calypso IVs are abundant so you should have no trouble finding one for parts.
