Thanks Bert, it was the rcgroups thread.
I am aware that I need to do a lot of reading about this electronic fuel metering system for two strokes.
As I may have mentioned, I have two converted industrial engines, one 26 cc and the other 40 cc.
I am still not clear if the Stihl M-Tronics solenoid can be integrated into the Walbro carbs that I am using, or not.
You may be able to suggest that this is possible or not. After all, if chainsaws are using it, my little 26 cc engine did come out of a chainsaw, so it follows that this is likely to be possible.
No pressure from me at this stage, I have a flying festival coming up in a couple of weeks and will be busy preparing for it over the next two weeks anyway.
After that, I will do more reading up on this.

Jim.