When I actually positioned the motor inside the frame, I could see that my earlier ideas for mounting the motor were not feasible. The motor is offset much further to the right side of the frame than I had envisioned. I will have to go with a face mounted bracket on the left side, and some type of clamp or belly bracket on the right half of the case.
After some careful measurements, I came up with a couple of designs. I'm pretty sure of the general design of the face bracket, but still working on ideas for the right side. I printed out a full scale drawing of the face bracket and glued it to a piece of 3/8" plywood. Using a Roto-Zip, drill and sand paper I followed the lines on the drawing.
Looking at the wood bracket mounted to the motor and the frame, it almost looks ready to use. But a second look shows some flaws. The orientation of the face bolts is going to interfere with the chain, since there is only about 1-3/8" clearance between the face plate and the frame. I will need to rotate the bolt pattern so one of the bolt heads is between the loop of chain. The other probem is the verticle position of the motor shaft relative to the swingarm pivot. The motor needs to go about 1/4" higher so the chain can be vertically centered on the swing arm.
Another thing that is obvious is that wood is not the ideal choice for the actual bracket. The weight of the motor twists the wood like its made of rubber. Fortunately, the final version will be made from 3/8" aluminum plate.
While I was making a mess in the garage, I decided to to cut the bottom out of the gas tank. This frees up some space for mounting electric compents and saves some weight. After breaking a few bits on the RotoZip I switched to the Dremel using little cut-off discs. While effective, the Dremel was excruciatingly slow, but the end result was pretty clean. Cutting out the fuel tank was almost cathartic. It's like I was setting the bike free from slavery to big oil.
Run El Gixxer, be free!!