Perkins 4.108 Replacement with Beta 43 or Yanmar 4JH5E

[AbacoBahamaMan]

So it's time to repower. The old 4.108 was too tired, and I think I have fried my brain over deciding between the beta 43 and yanmar 4JH5E which seems to be rated between 53 and 54 or maybe even 56 in europe depending on which dealer you talk to. Cost really isn't an issue between the two, but I was looking on some input from anyone who has either of these engines. Right off the bat the yanmar torque curve from the tech data sheets runs the beta 43 into the ground @ 2000 RPM. I sat down and plotted out both engines on a common graph and at the same RPM, the yanmar has more power, more torque (by a big margin) and even consumes slightly less fuel (is that possible?) The fuel consumption @ 2000RPM I have looked over several times and it really does look like I have the data right at less than 1Gallon/Hour at that speed. Can anyone verify this in the real world? How about reliability of these two engines? Parts availability? upkeep? I have read that the marine additions to the kubota block used in the beta engine have failed on several forums due to quality of parts used, but that might be with older generations. Again anyone have first had advice on this? Probably the biggest question so far is which 3 bladed fixed prop should be used with this engine and a ZF15MIV with the 2.13 ratio. Again, I have been told different information depending on who I talk to and would rather buy a prop too large and cut it down than buy a prop too small and have to replace it with a larger one. The middle ground on the range seems to be a 18"(max) X 10 to 13 pitch. Any inputs on the proper pitch would be great.
Thanks for any input.

[John A]

I repowered from the 4.108 to the 4JH5E. Performance wise I was quite satisfied. I was a little distressed at the modifications required for the conversion as they seemed to be never ending. I kept my two bladed 18" fixed prop.

[osirissail]

The Yanmar is top of the line but also carries the top of the line price. The Beta Marine is a good second choice when budget is a major problem. I have a Beta Marine genset and love it. The service and assistance by BetaMarineNC was excellent and made a big difference in my choice.