No Steve the Oil temp sensor in the front rocker cover of the 620 does the same job.
to go with the 1.6m ECU You would need the 748/916/ST2 harness, MAP Sensor and Air Temp sensor

Thats good news then! i have a st4/2 1.6m ecu and harness complete in my shed!
Ecu has a ducati performance ST4 eprom fitted at the moment.

The 4.5mm longer stroke of the ST4 may cause ignition timing issues, but then again the EPROM may have a advance curve that works, hard to tell until its tried.
As for fueling which injectors did the ST4 use was it the green ones, if so a Powercommander should easily be able to sort out the air/fuel ratio.
Only other concern is the TPS as the connector is different but the signal should be OK as the Mathesis can test both

Thanks Kev
Prob easier to get hold of a st2 harness.
Good thing about 1.6m is you see lots of s/h pc3's up for sale for this type ecu.

After a busy period at work as you know Kev! We will meet so you can collect to forks :)
Questions!
1.6 ecu fitted with st2 eprom and fit PC3 ?
st4 loom (with green injectors) can be used on the 2v injector bodys/injectors ?
The st4 loom complete with MAP and Air temp sensor will work on a 620 engine ?
Hope this makes sense ? Just finished a nice bottle of red :)

Steve, injection ECU doesn't give a dam which engine is in the bike, all it cares about is having Suitable impeadance injectors, suitable TPS, suitable engine pick-up, suitable air temp sensor, suitable engine temp sensor, suitable MAP Sensor (some ECUs do this differently), Suitable harness and correct resitance coils.
Then its just a matter of having a fuel and ignition program loaded into the ECU or EPROM (possibly aided by a PC3) to suit the choosen engine

So I would suggest a 748 EPROM if using a 1.6M ecu as the engine uses the same stroke as a 620, I would also go with ST2 or 750/900ie green injector throttle bodies and TPS, the latter is the same TPS as used on 748Rs so works with a 1.6M ECU

And in answer to your email, yes I still have a 620 engine available