Heck, no mention of a lighting requirement. It's those pesky spark plugs that are the problem.
Convert to glow plugs.
Use straight methanol.
Up the CR.
Maybe trim off some cooling fin material (or block airflow through them to help retain heat)
Just need a small battery to make the plugs glow for kick start. After that, the platinum in the plug will catalyze the methanol when the A/F mixture is compressed. Turn the staring battery off, and drive away.
Want more power? Add Nitro.
Won't get much lighter than that.