How fast??

[Crappie 1]

I just bought a new 2009 Starcraft 16' boat/a side council and it has a 30 HP Mercury 4 stroke. It starts great and runs good and trolls good. Heres the problem, top speed with 2 of us in it is about 17 mph Were both under 200 lbs. and don't have any heavy gear. Any ideas? It runs great, just seems slow to me.Thanks

[wannabe fisherman]

if it's a glass boat then that might be about right with a 30HP JMO
I push a 17 footer with an 85 and it gets about 35.

[Crappie 1]

No, it's aluminum. It's a brand new 2009 that never sold, so I'm the only owner.

[Sam]

Is it a GPS speed or just the reading from the speedometer? The speedometers are usually incorrect. I have a 16 foot Carolina skiff with a 25 HP Honda 4 stroke and I get 27MPH with two around 200lbs each. Do you know how much your boat weighs?

[huntinslabs]

You might be overpropped. What rpm's are you spinning?

[Crappie 1]

It's a GPS reading. The boat is 72" wide by 16'4" long. It is a heavy boat. I just got back from the dealer and the maxed out RPM'S is 5500 with the current prop. They lake tested it with just the mechanic in it and it ran 24mph. To go to a smaller prop would over rev the motor. I was used to my 14' it had a 25 Johnson 3 cylinder on it and it ran about 23 mph. This boat's much bigger and only added 5 HP. Top rpm's is between 5500 & 6000 for this motor. That's what I was told anyway...

[Wind Knot]

Everything you're saying is making sense, except the part about going to a shallower prop. I presume the mechanic ran the boat by himself and lightly loaded, meaning he hit the low end for rpm's with about as light of a load as that boat will see. The smart money says that you'll rarely, if ever, run a load that light. I would rather see a boat that ran 6,000 rpm's with an unusually light load and 5,500-5,800 rpm's with a regular fishing load. It may be good for a few mph's.

I would also get under the boat and make sure there isn't any slag that's disrupting water to the prop. Finally, trim her as high as she'll go. Less wetted surface= faster boat.

[huntinslabs]

Everything you're saying is making sense, except the part about going to a shallower prop. I presume the mechanic ran the boat by himself and lightly loaded, meaning he hit the low end for rpm's with about as light of a load as that boat will see. The smart money says that you'll rarely, if ever, run a load that light. I would rather see a boat that ran 6,000 rpm's with an unusually light load and 5,500-5,800 rpm's with a regular fishing load. It may be good for a few mph's.

I would also get under the boat and make sure there isn't any slag that's disrupting water to the prop. Finally, trim her as high as she'll go. Less wetted surface= faster boat.

Exactly!

[Crappie 1]

I guess everthing's just like it's supposed to be, so, will just leave it as is. It's a great running motor, and I love the boat, just not any changes that would help much. Thanks for the information and the posts...

[Jeffunder]

I have a 16 1/2 foot heavy aluminum boat like you and had a 55 johnson two stroke..it would run 28mph..I blew that engine and put a 90 horse yamaha and it now runs 38-40 mph, so I would say you are right on with the motor that you have..