23 Fish Machine repower advice

[kalapuka]

Hello BlackMan owners,
I have just both 23 Fish Machine in Kona with a worn D3 170 at 7300 hours. So I am going to repower the boat. My thought is to put a D4 225 with a due prop leg combo.
But I am also thinking of putting in a D6 because of the weight. It will also be 300 HP witch is twice what the boat has now.

My question is

1. Will the 23 footer hold the weight.

2. How is the Blackman 23 in following seas ( heaver engine better down sea ride )

3. This boat is 7 feet wide, Is this the right width I thought they were 8 feet wide or is that the 26 footer?

[NoSlack]

I've had my 23' for 25+ years with the old AQAD40(150HP) engine and Duo Prop out drive. I believe my package is just under 1200 pounds and can't imagine going much heaver. I think it would be a bad idea to add more weight to the back end and have the deck drains below the water level.

Width is 7' 2" at the stern.

When considering horse power, you need to ask yourself how fast can I go on an average day and how far am I traveling to get to the grounds. Here in San Diego, we travel 10 to 50 miles offshore at 18-25 knots on an average day. 170 HP in the 23' would be about right for our conditions.

I don't know of any 23' owners that re-powered with a lot of horse power. There are several 26' owners that went up over 250HP and are to scared to use the extra HP they paid for. The hulls were designed to run 15-20 knots and get a little scary over 30.

Mike

[kalapuka]

Thanks Mike
That is what I needed. I will stick with the D4 225 hp and duel prop leg.
I was worried about the following seas that I have to go through when coming back from the day of fishing.
I just hope the boat will not breach that bad.
But I will Repower with the D4 package.
It’s crazy but you cannot don’t a Yanmar or Cummins Repower ship out here in Hawaii. They all want to put outboards on the boat.
Never agai will I use outboards. They just that twice the maintenance and fuel consumption was not all that great when I ran them.
Anyways thanks for the advise.
Eric

[DOGHOUSE26]

With the extra power you won't have to rely on your trim tabs so much anymore; you will be able to cruise comfortably @ 20kts without pushing the motor too hard. Your tabs will be close to all the way up and the boat won't dive into the swell in a following sea. I have a D4-260 in my 26 and its a completely new animal; I never knew how underpowered I was before with the original AD41P 200HP. The D3s are 5 cylinders and the D4s are only 4, so it might even be lighter than what you have now. The D6-300HP has a tendency to eat up outdrives fast!