I was able to get the engine stand completed and engine running again.
The old exhaust system was pretty much cracked and fell apart when I tried to remove it from the three wheeler so I had to make a “new” setup. I bought the cheapest muffler I could find on eBay ($15 moped muffler) and some spare steel tubing I had and I welded up a temporary exhaust. I reused the old exhaust flange that mounts to the engine but I would like to replace all of it with new material when I finally transplant this engine in the go cart.
I then mounted the fuel tank I bought on ebay for $6. Fairly tiny with only 1L of capacity but the tank was pretty cheap and doesn’t leak… can’t complain about that.
I made the fuel tank mount out of some old aluminum sign material I had forever. I think I have been holding onto that material for over a decade now! Knew it would be useful some day :)
The fuel tank mount is designed to be unscrewed giving me more access to the engine when I start disassembly.
And it fired right up after filling the tank up. Glad I got the wiring right!
What is next is to disassembly and clean the entire engine. Once it heats up it smokes pretty good so I will need to at the minimal replace the piston rings and lap the valves. Probably end up honing the cylinder walls for the new rings.