better to find a half cut, and take the engine out from it.
just find a matching replacement engine. no need to worry about wiring at all. it will then be plug and play.
honda engines are quite strong.
what damages them is water in the radiator, no timely maintenance, over heating the engine... direct fan, no thermostat, CNG
if done properly, engine will last long.
mine has done 214000 kms without even a trace of smoke. always been on petrol, auto fan, operating thermostat and coolant. basically running on the same settings it left the factory.