Another option for you bladder users

I recently tried this experiment and I'm quite happy with the results. I've seen this mod done using all JB weld but I didn't want to do that. This would work quite well with a Norvel equally. I use APC type props. One day after breaking one, we've all been there as all you have to do is look at them and they're broke. I thought, maybe I could make a adapter out of the broken prop hub and glue it inside the crankcase and drill and tap it for use with a TD needle valve setup.

I ca'd the hub to a hardwood stick and proceeded to rough it out on the bandsaw. I then carefully sanded the part as squarely as possible using the prop hole as a guideline to keep the overall piece centered. Your eyes will pick up if your going off center. I sanded a slight taper into the small rectangle and this allowed for a friction fit. I JB welded the small rectangular piece into the case with the crank in place and cotton to prevent any JB weld from going into the crank area.

Once dried 24 hrs, I proceeded to drill the bushing in which the prop hole easily assisted my drill bit. I then ran a 1/4-32 tap through the adapter. This is noticeable in the pic as the APC prop hub is the dark gray areas. I slightly radiused the corners so that it fits quite nicely into the case.  The adapter now becomes two pieces due to the 1/4" tap and the tap cuts and threads into the side walls of the case. This mod worked exceptionally well and a Kirn Kraft setup can now be used for extremely reliable and simple pressure useage. You can run stock or modified venturi's. I then checked to make sure the venturi was sitting square on the case and a bit of filing of the case was required. My dad always called the file the" Nicholson mill ". I never really new why he would say that but later in life I figured it out and it made me laugh.

After the venturi is screwed in, I lay the case on it's side and fill the holes on the side of the case in which the needle valve bolt or spray bar passed through. This is simply done by using JB weld. I don't clean the threads on the Cox venturi in fact I oil them first. This way the JB weld doesn't stick to the aluminum. Don't panic, if it does as it will come loose if needed to be removed. Ken