Originally Posted by John_M_

Yes, hi CO is the result of incomplete combustion... advancing ign increases the burn time, also raises combustion temps... too advanced, NoX forms, but these little engine are more tolerant due to such small displacments... as mentioned in the past, these model CDI systems have a fixed ign curve, configured for a 28 degree base timing... With that small putt putt setup you have in your boat, you probably can get away with it fixed at the optimum timing position, with manual retart for startup... if you could monitor Co2 as well, then that would give you a better reference to combustion efficency.

So I'm going to share some progress and improvments I have made to my CDI with you guys... now running 2 seeeduino's in series, not in cascade, but shares data... first seeed handles ignition timing using ign timing reference tables / cross referencing to rpm with zero interrupts... the other seeed manages rx channel data to manage throttle arm to lockout startup with the throttle stick too hi, similar to how electric esc's function... trying to include sbus2 for other future features... it will have standalone programmability with a separate plug-in device, with program buttons and a small LCD screen, with 8 programmable ign points, and programmable rev limiter... I have someone working with me on it who knows programming a bit better than I... I'm also working with another inividual that may produce theses at a reasonable cost to sell, under $100 USD... a bit larger in size than what we have now ( not by much, just a different shaped enclosure ) and about 1 ounce (28.35g) heavier... 38k spark voltage, multi- spark output with flash over protection, with 3 banks of hi voltage ceramic capacitors switched by the seeed based on rpm... I'm tickled to see this come this far, and it has taken a lot of my spare time.