[malc9141]

Hi Paul, That's a nice post, thanks. I'll have to think about the meat of your message: ie, the switching.
(I do remember the solid state spark controllers - a friend built one successfully. But I did not!).

You say:

Also, (1) what are you going to use to supply the fuel under pressure. Even with a big flywheel I don't think a single cylinder motor will stand the (2) compression load and the high pressure pump load. Still, if the flywheel was very very very big......But, then (3) how do you get it spinning in the first place?

If I understand your questions, (1) the fuel comes off the Renault Clio pressure pump. I've talked to people about this and I might be wrong but I think there's a lot less work to run one injector in a 300 cc cylinder. So the drive load should be OK - after all, a car starts by the battery turning the engine over, and thence the pump. It doesn't seem a problem. Pressure is only one part of the calculation. (Power needed = pressure X volume delivered, and that's very small). But I'm always open to correction.

It's a two stroke, so both valves are open for the lower 120 degrees or so of crank angle, so there's a loss of compression there. I had thought the initial problem might be getting it fired up (tho' the gloplug is there to help) with lack of compression.

Once firing, it will be a tragedy if it self-destructs! I just hope the robust Lister-Petter unit will stand the shortish experimental runs, to test the cylinder head design and overall concept.
(3)I would turn it fast on a starter ring.

But may I say I welcome this chat enormously, so thanks.

Malc