Bill what about the 170cdi running temperature. Is it significantly higher then the normal glow version? I mean at the lean setting you are running.

I made some experiments with a runtronic ignition on a YS140 years ago, and found it hade many positive effects (smoother running, no kick back etc). It could be run much leaner, like you have experienced, but temperature went up more then I expected. I felt it was a bit tricky to adjust the engine as there was less feedback on what was a good setting. I feared it would run to hot if the setting was to lean. Perhaps a built in temperature sensor could be useful (integrated with the cdi unit), or just a hand held IR thermo. I really would be scared to run a 170 cdi on 5% oil and a lean setting

Another thing I wonder is if you have had any problem with oil clogging up the spark plug during storage, causing problem to start the engine? I understand inverted spark plug engines can have this problem. Also if the engine gets soaked, the oil/fuel can kill the spark, causing difficulty in starting. I think this is all much worse on two strokes, but have you had any problems on the YS?

It’s a shame YS had to feel the pressure from electrics in order to start this development. It should have been done years ago.

/David