We are in the process of replacing the engine on our fishing boat and went through ahead with a Yanmar 4JH5E with a KM4A gearbox. When we received the propeller (new Vetus P4B18X4) we found that it was a left hand propeller vs the right hand 4JH5E engine.

The mechanic informs us that since the ratio of the gear 2.14/2.14 this should not be a problem as we can effectively run the gearbox in 'reverse' to go forward.

I'm not 100% comfortable with this as a permanent solution so would greatly appreciate your input with regards to if this is acceptable or running the gearbox in reverse most of the time will end up in damaging the gearbox in the long run.

Many thanks,