Thank you all for your interest
there have been lots of ups and downs on this project
but I am getting there
This version works well but there are still some problems with the helix metering pump and petrol, benzine, gasoline, the non linearity due to leakage past the helix and leakage past the plunger that affects the lubrication of the pump drive system. Diesel fuel would not be a problem so I would keep with the helix for my diesel work as it resolves the injection timing issues. I have a stroke controlled design for petrol injection that I will try as the next stage.
The 80W I could measure is what it is. The efficiency of the motor/generator is probably no better than 50% as MJM460 says, and it is also not sufficient to load the engine fully. I have two versions of this motor with different windings. The Torpedo 850 is used on my 25cc horizontal engine, geared up 4-1, where I have achieved ~120W at an engine speed of 3000rpm, so a motor speed of 12,000 rpm. The twin uses a direct coupled Torpedo 800 running at max 8000 rpm. Replacing the 800 with the 850 reduced the measured power to ~49W (7v 7A). Real maximum output is probably 250W or more but hopefully I can get enough output for a tractor at lower revs, 8000rpm in not exactly tractor like