Originally Posted by chef2sail
The yanmar 3ym30 is the direct replacement for your 3qm30 as well as our 3gm20 on our C&C 35 MKIII 1983. Since the engine compartments are so small and almost custom on our boats I would say its best to go through with the Yanmar.
The Beta is a great engine too and has been getting good reviews.
I will second this. The Yanmar is a marine engine right from the start & if you're going down the repower road, swaping a yanmar for a yanmar is the way to go.
Beta's, great reviews but it is a kubota motor that has been marinized.
I have nothing bad to say about kabota engines, had one in a firewood processor that we beat the snot out it & it keep runnning day & day out. For the record I wouldn't buy one of their tractors, John Deere fan...
For me, if you look at many of the 70 era motors, many of them where tractor
motors that were marinized & that's the issue I have with Beta. It's not a boat motor.