Problems with V2 conversion turbo upgrade

I recently upgraded to turbo fins and V2 sprockets at the same time (the drums were already V2). The easiest way to do this seemed to be Roadrunner's excellent "field sprocket replacement" instructions to avoid removing chains or drums:
http://www.hobiecat.com/community/viewtopic.php?f=11&t=12941&hilit=replace+sprocket

The instructions seemed clear enough but , as they say, "the devil is in the details". The first detail problem encountered was that the screw holes in the front shrouds would not line up with the holes in the sprocket. I had to elongate the holes in the shrouds to enable installation and they still don't fit well, a nuisance but no biggie. The front shrouds seem to be mainly cosmetic anyway.

A much bigger problem occured installing the new, longer, masts into the new V2 sprockets. The threaded end of the masts fit very tightly into the brass inserts in the sprockets. So tightly that it was necessary to use a big screwdriver to screw the masts into even the unthreaded portion of the brass insert. The stainless masts seemed to be cutting their own threads in the brass. I eventually got the masts threaded and "loctighted" into the sprockets.

Installing the fins on the masts, however, I discovered all may not be well. The fins don't seem to seat as closely as expected to the sockets. See photo below:


I'm afraid when the masts screwed in far enough the "self threads" reached the real threads and didn't line up so the mast stopped before entering the real threads and is now just threaded into the self-cut threads in the insert sleve. The masts seem to be quide secure and solid where they are.

The question is; what did I do wrong to get into this mess and how do I fix it? Are the fins on far enough that I should just not wory about it? It would be hard to get the masts back out of the sprockets but I'm sure its possible. I expect this would leave the inside of the brass inserts in poor shape due to the brass that was "rearranged" when they were screwed-in. Should I try to ream the unthreaded part of the inserts with a drill and then try to screw the masts back into the real threads?

Why might this have become a problem in the first place? Shouldn't the (brand new) masts fit into the (brand new) sprockets so they thread-in properly?

By the way, I also tried a couple of improvizations that seemed to help. Using a Dremel I cut the screwdriver slots on the end of the masts deeper. I had already cut the slots deeper before threading in the masts, otherwise I probably couldn't have gotten enough purchase to screw the masts into such a tight fit without using a vice grip, which no doubt would have created burrs on the mast. It would be good of Hobie to make these slots deeper in the first place.

Also, Roadrunners instructions suggest marking a line on the end of the sprocket shaft before removing the set-screw to aid allignment on re-installation, a good suggestion I doubt I would have thought of until it was too late. Taking the idea one step further, I used the Dremel again to cut screwdriver slots into both ends of the sprocket shaft instead of just marks. (actually it is better to just mark the line before removing the set-screw and cut slots into the lines later when the shaft ends are more accessable) This allows several advantages; serves as a permanent alignment mark, provides an easy way to turn the shaft into alignment, was useful to wiggle the shaft back and forth while tightening the set-screw to insure the screw is securely bottomed, could be useful to wiggle the shaft to loosen corrosion or grit while removing rather than just bang harder.

Anyway, any suggestions regarding the mast threads are welcome.

I just did mine last weekend--I was even worse off as i was following a youtube link onhow to do it--but they were using the old, unthreaded version and it took me awhile to figure that out . Ill check and see if my fins look like yours in terms of how far the masts are in.
T2

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Fish worship--is it wrong?

To double check your work, both masts should extend out from the sprockets an equal distance. This distance is about 13 and 1/16 inches. From your picture, it appears that your rear mast may not be fully seated. If the mast is too long, the fin does not get sufficient wind-up space to twist properly.

I would remove the mast (use padded Visegrips if necessary), clean everything and run the mast back in (again with a Visegrip assist if necessary). You can mark the correct insertion point ahead of time to verify that you are in all the way, or just measure when you think the mast is seated. When done, remove any burrs from the mast (including the slot tip) that might dig into the fins.

The mast is definitely a tight fit. The newest masts are electropolished for a little better fit. viewtopic.php?f=11&t=16992 but yours will work just as well -- just a bit more difficult to install.

The V2 sprockets are fractionally larger in diameter, making the holes in your old sprocket guards misaligned. IMO, Hobie should include correctly drilled (or pre-installed) sprocket guards with the kits.

Your slot in the sprocket shaft end is a great idea for alignment and adjustment!!

I took the fins off and measured the mast lengths. The front one was about 13 1/8, that seemed close enough so I left it alone. The rear mast measured 13 5/16 or about 1/4" too long. With a pair of vice grips and considerable effort I was able to screw it in to 13 1/16". Thanks Roadrunner for the measurements, I feel better now. Of course the Locktite is compromised but, given the difficulty I had getting it in, I can't imagine it coming out on its own.