Bigger motor performance estimate?

[keninaz]

I have a heavier 14' aluminum boat, but it rides great as a result.
I bought it with a 9.9 HP 4 stroke thinking that would be enough motor for fishing but the performance with a stock prop was only 12 MPH on average with the normal load in the boat.
So I sold the 9.9 and picked up a 20 HP (The boat is rated for up to a 30HP).
I have not had a chance to take it out yet and break it in as I had bypass surgery on my heart and an implant done recently and I am awaiting clearance from the docs to resume normal activities.
Anyone care to guess as to the new top speed with the same load? I am hoping for quicker planning and maybe 18-20 MPH.

 

[Alumarine]

You might get as much as 30 mph out of it lightly loaded.
I'd say easily low 20's though.

A friend has a 16ft lund with a 20 and it gets to 27 mph with 2 light people.

 

[Watermann]

Difficult to say exactly not seeing any pics or info on how the boat is laid out or even the hull design type. 12 MPH isn't enough speed to plane so the 20 HP will seem like a speed demon in comparison.

 

[keninaz]

Interesting. When balanced out with a pretty good load it planed at about 8-9 MPH with the load we take.

I will be very happy to have 18 MPH or so.
And to make things easier on my older body this time I went for the electric tilt and start!
Looking forward to getting back to fishing.

 

[roffey]

As the OP already has the motor it just debate. With that in mind I an going to guess 26 MPH with a GPS phone. That speed on the water in a 14 foot boat will seem like you are flying. I bet it will be night and day and just pop up on plane and then go...

question, do you have electric start?

 

[jimmbo]

We used to have two 14 foot car toppers, one with a 1979 25, the other a 1980 35. they went about 29 for the 25 and 32 for the 35. Our engines were crank rated, your 20 hp might be very close to our 25 in performance

 

[airshot]

My 14' starcraft alum had a 15hp jonnyrude and she would do 22-24 with just me in the boat, with 2 adults and fishing gear around 17-18mph. Would plane out around 14-15mph with my handheld gps.

 

[keninaz]

As the OP already has the motor it just debate. With that in mind I an going to guess 26 MPH with a GPS phone. That speed on the water in a 14 foot boat will seem like you are flying. I bet it will be night and day and just pop up on plane and then go...

question, do you have electric start?

Yes, as stated with the 20 HP I opted for the power tilt and start. Medical problems and age make it almost a requirement now. The only downside of doing that was that from the 9.9 to the 20 the weight of the motor increase from like 84# to 180#.
I did fire the new motor one time when I got it last Jan after installing it on the boat. That was just before bypass surgery. I sure like the newer and quieter 4 stroke motors.

 

[roffey]

great, I think you will enjoy it. New motors these days are so much easer to run. With electric start and trim it will be just that much nicer and will get you back on the water that much sooner. What better way to convalesce than on the water relaxing.