Sprocket V2 Threaded w/guard repair on Tandem Island

I want to replace a turbo fin I lost. Does the replacement fin come with a screw on the top back side to latch on the fin to the sprocket? Because the round nut does not unscrew all the way? It's locked on the end which prevents the nut from spinning off.

Temporarily, I want to install a shorter fin until I get the turbo fin. But the long metal rod cannot be unscrewed as the whole base just spins. So I removed the chain, but I cannot remove the installed Sprocket V2 and install a new V2 with a shorter metal rod option. Is there a trick to uninstalling the Sprocket from the TI and intalling another one for the shorter fin? The installed V2 seems to be locked on the ends (?).

This all started when I lost a fin : (
Thank you for any informational help.

ST and ST Turbo fins come with the nut and screw installed.

The fore / aft sprocket shaft is held in by a set screw in the middle.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Awesome Matt.
Thank you.

Mel Buenaventura, Co-Captain
Vancouver BC Hobie Island Club