Repowering K-K Manatee

[Serene86]

Looks like I may have to replace engine and genset. Recommendations?

 

[healhustler]

Assuming you had an original Volvo 90-110 HP Diesel, and you actually want to replace vs. rebuild, your engine selection is limited by RPM range and engine room height restrictions. If Insurance companies are involved, the typically go with later model Volvos. If you’re looking for a used replacement, the Yanmar 4JH (85-110 HP) and 4LH (140-235 HP) diesels are economical, fit well, and give very similar torque & HP curves. The 4JH series are plentiful and take-outs can usually be found in FL. The 4LH series are harder to find but the 140 HP version (4LH-HTE) is also an appropriate swap. There are at least two of these LH repowered Manatees here in Sarasota for you to look at.

The old faithful Kubota 85 would be another candidate, but It’s a bit too tall I think. John Deere 4045 is a dream but is also too tall. The first 12 or so Manatees had 50 HP Perkins, which took the boat to hull speed but there was little power left for additional accessories, so I wouldn’t recommend it.

Try to keep in mind that the only thing that a manatee will do with more than 110 hp is just dig a bigger hole in the water. The top speed of my boat with a clean prop & bottom is 9 knots and that is with the swim platform totally submerged. Don’t waste your time & money on more horsepower.

You mentioned Genset replacement too. A good used Northern Lights 5 KW can be 5K or more. You may also want to consider moving the unit out from beneath that terrible space below the galley and into a new hatch in the veranda. It changes everything.

 

[DavidM]

Check out Beta Marine's engine line up in the 90-115 hp range. They are slow reving, mildly turbocharged engines which should give long life.

Also Yanmar as a company doesn't support repowers much. Beta Marine probably does most of the business as repowers.

David

 

[Mac2]

Clearance is a big deal. I put a 5kw Westerbeke generator in my Manatee and I had maybe one inch of clearance. It was the two stateroom model, but I think they went into the same spot. I was very happy with it. I used it for several years before selling the boat. The only issue I ever had was when I was in big seas and the generator shut off due to the location of through hull and it sucked air. I fixed the problem by adding a scoop type through hull. The generator did a good job protecting itself.

 

[healhustler]

David is right. Buying new, Beta Marine is the repower expert. The Kubota based 83HP at an advertised 23.3” from motor mount base to top of engine should fit under the hatches. As your Volvo is a 3600 RPM engine and the Kubota being a 2800 RPM, your trans ratio would and/or prop would need updating as well. Beta would calculate all that for you. With our Yanmar also being a 3600 RPM engine, we run the same ratio, shaft and prop as the original Volvo.

I know nothing about the Beta 90-115 HP.