1990 25' MV Re-Power - How Much Can it Handle

[aalbert]

So since one motor on the boat needs replacement (currently 1990 Yamaha 150 carb motors), the question is do we replace both, and if so what are our options?

Boat will be used in the waters around Miami, with 3 adults and 3 kids, 2 dogs... Preferred fishing is trolling / drifting, not a lot of 50 mile treks out to Bimini or anything, however the maneuverability of dual motors, and redundancy of a spare motor make the owner (my buddy) lean towards twins.

In reading other posts, it seems as if the boat is likely rated for 325hp, but is that rating a hard number, or is there a lot of room?

So will she take twin 175s, 200s, 225s, 250s? .... If sticking to one motor and a kicker, is 250hp enough, or does he need to look for a 4 stroke 300hp? Any motors purchased will be used, since down here in S. Florida, you can pickup motors for 2-4k each with lots of life left in them (and 4 strokes for 7-10k).

What kind of performance have folks gotten with twin 150s vs. 200s?


Thank you in advance.

 

[moose8420]

I recommend 300 hp. My single F300 does a great job pushing my 99 2520 SCMV

 

[aalbert]

As a follow up, it looks like he is going to buy another matching 150hp, or resurrect the existing 150hp motor.

 

[warthog5]

I guess this is answered already, but. If it was mine.

A single DF- 300 Suzuki. CLEAN the TANKS! I can not emphasize that enough.

No matter if you jave old or new motors.... Single or twins. Bad / dirty fuel will kill them all.

Why the single?

Less weight where you don't want it.
Less drag in the water from not having a 2nd foot in the water.
Less maintenance
Easier to fish around.
Better fuel millage

 

[Megabyte]

I guess this is answered already, but. If it was mine.

A single DF- 300 Suzuki. CLEAN the TANKS! I can not emphasize that enough.

No matter if you jave old or new motors.... Single or twins. Bad / dirty fuel will kill them all.

Why the single?

Less weight where you don't want it.
Less drag in the water from not having a 2nd foot in the water.
Less maintenance
Easier to fish around.
Better fuel millage

Agree with all of this, but if your hull is the older 14 degree deadrise as mine is, a 300 will get you a very little performance gain than will a 250.
There is a 'terminal speed' on these hulls, and more horsepower does not always equal more performance.

For example... The fire department I retired from had a pair of Parker 21SE rescue boats.
One had a 225 Merc on the back, the other a 150 HPDI.
The 225 hp boat was only 2 kts faster than the 150 hp boat at WOT.

Something to consider.

 

[moose8420]

I would just like to comment, going from a F225 to a F300 was a large improvement for my 14 degree dead rise hull. My top end changed from 38mph to 42mph. but my cruising rpms dropped from 5100 with the F225 to 4200-4300 with the F300. My cruise speed has gone from 27mph to 31mph with a 40% increase in my fuel economy. I would also like to point out that if you run with a heavy load often the higher horse power will be more efficient regardless of the terminal hull speed.