I have had Nanni 14hp 2.50HE for five years in 6000lb 27ft twin keeler with no problems. Hamble Yacht Services can maintain and have spares. I believe UK agent is somewhere in Norwich.
I re-engine, removing a Volvo sea water cooled , and fitting a Nanni 23hp fresh water cooled. Very satisfied. Agents are A R Peachment Marine, Riverside Est. Brundeall Norwich (01603)714077 Very helpful Regards K