Yanmar 3JH replacement options

G'day all

I'm new here (been lurking for ages). I'm interested to hear from folks, and sailing cat designers / builders in particular, what they think of the changes in Yanmar's sailboat engine range. As you would know. the venerable 3JH engines are to be discontinued and replaced with a 45hp 4 cylinder common rail (electronic) engine. This is due to them having to comply with EPA tier 3 as of Jan this year (the new engine complies with tier 4) whereas the 3JH is only a tier 2 engine. The snag is the new 45hp weighs 230kg with standard g/box....or 260kg with an SD60 saildrive. That is a huge increase in weight over the 3JH which weighed 168kg with a standard g/box. So for those of us that require a +/- 40hp saildrive solution (shaft not an option unfortunately) in weight sensitive performance sailing cats, what are our alternatives now?
To recap options:
1) The new Yanmar 4JH45 + SD6O = too heavy
2) Beta / Nanni 38/40hp + twindisk SP60 = great engines, has tier 3 compliance, good weights, but serious question mark on the saildrives. Beta supplies them with a 100 hour per annum operating restriction...which doesn't exactly fill one with confidence in the drives and its not a restriction one can pass on to a client with a strait face.
3) Volvo D2 40hp + 130S saildrive = well established, has tier 3 compliance, acceptable weight, good saildrive but the engine perhaps perceived to be not as good as yanmar / kubota base engines?
4) Lombardini 40hp + lombardini SD = excellent weights (best around), tier 3 compliant, but largely unknown (to me anyway) track record of reliability.
5) Beta / Nanni 38/40hp + 130S saildrive = this is possible as both companies have adapter plates to be able to mate their engines to volvo or yanmar drives. But could get expensive having to purchase engines and drives separately instead of as a packaged solution.

Any other viable options I've left out?

I feel yanmar has dropped the ball here. The way I see it only options 3,4 and 5 make any sense realistically, unless one is happy with over half a ton in engines for 90hp max. Parts availability is of course another concern, but then in the remote areas where these boats would operate most of the time, it would most likely be a case of freighting parts in that were not on board regardless of the manufacturer anyway. So I'm keen to hear what are others are doing/planning in this regard?

Cheers
A

 

The problem I see with reliability is the sail drive. Basically an outboard leg immersed 24/7/365 built with dozens of metals.

Any chance of a lifting 4 stroke gas outboard engine?

Zero drag under sail , Zero electrolisis except when actually in use.

Outboard service lives today are far improved from 50 years ago, 3000 hours in commercial service is not uncommon.

Just a thought.

 

Outboards are a good solution in certain instances, ie smaller boats up to 20-25hp max power requirement. This unfortunately isn't one of them. The boat is 51 foot, light enough and very easily driven, but still requires around 40hp. Unfortunately there is no 40hp high thrust outboard with a final ratio suitable for this application. In addition, an outboard mounting solution for this boat would be problematic. Its a good idea in principle though.