Tohatsu M50D2 Intermittent runner !

[davrix]

Hi, I'm back on the water in the Zapcat!.. but not for long as the Tohatsu M50D2 has gone intermittent. She may run properly, she may then stall, restart and run well or restart, idle, bogging and stall once in gear, or not start at all!

I've got my picoscope out and can see the triggers for the timing are all there ; the exciter coils are producing nicely when disconnected from the 'ECU'

However when we connect to the ECU the trace turns very unbalanced...

I wonder if this is due to some fault within the CDI unit ? Would any one have any views on this ? the exciter coils out put is said to be rectified and stored in a capacitor - is there a way to monitor this voltage ?

There are outputs to the coils, however these seem very short duration .. very little dwell time for the coils to charge up .. perhaps a burn time of 600uS... Any thoughts ?

Anyone else used a Picoscope to see exactly what's happening on their engines ?

Dave

[Roflhat]

Not used to all the hi tech stuff you've got going on there, but the coils on tohatsu 50's are notoriously crap. For reliability you want to replace them with different ones, tohatsu 70, Yamaha 90 etc. Nakuru coils too.