Issue with the speed of my new (used) boat

[toned]

So I recently picked up a 99 Lund Rebel (560 pounds) with a 2003 honda bf20d motor

I am kind of shocked by how slow this boat is and unsure how to proceed with resolving this problem logically.

When I first got it, I changed the oil, filter, plugs and foot oil...the basic maintenance...it fires up right away and sounds real healthy idling, and under throttle (idle) it sounds as healthy as can be

first time out, it was windy...I was maxing out at 11mph...the motor sounded like it had more to go, like it was running at half throttle...I made sure the throttle plate was opening fully and it is...I checked the fuel filter and it's clean and flows well...I had realized that I had maybe left the bleeder valve partially closed on the gas tank and chalked it up to that

I've been out back once since, it was a calm day, I was doing 15mph, and again it sounded like it had more to go...made sure the gas tank is open all the way...I left scratching my head

the prop that's on it now is a 4 blade honda prop

both times out was me (190 pounds), my buddy (280 pounds), and our tackle (50 lbs)

to me, this is under performing, but I am not sure who I should take it to, or how I can start troubleshooting this issue myself

any ideas? does this seem slow or normal?
anyone know if/how I can hook up an RPM gauge to the motor to see if it's actually getting close to the max RPM it's rated for? I tried searching online but no clear answer

I am really stumped here, and not sure how to proceed.

[lape0019]

You are going to need an RPM guage to verify your WOT rpm's and that will be where to start. If it sounds like it has more to go, than chances are, it is over propped and a smaller pitch or even the same pitch in a three blade will increase RPM's.

Secondly, which model of a rebel is it? Tiller or SC? What is the Max HP for the boat?

I ask this because I have a friend who has a 2003 Lund Rebel 1455 side console rated for a 40 (which it has) and I think he gets about 35MPH out of his setup. If you are running half of the HP and getting 15MPH, I think you might be doing pretty good but you will never know until you get a tach installed to see what your WOT's are at.

[toned]

Thanks for the reply

It's the tiller version.

The boat is rated for 35HP (and 5 people) in the US and 30HP (3 people) in Canada

I will pickup a Tach, install it and report back

[smitty55]

I think the boat is just way underpowered for it's weight. My 14 ft Yukon tinny which weighs about 180 lbs will get me around 23 mph with a load in it with an older 20 hp. That is with a lower pitch prop so I could troll for Lakers. So if your boat is that heavy (560 lbs) I'm not that surprised you only get 15 mph with a 20 hp. So like Adam said a prop change may be what you need to get more speed. Or even better upgrade your engine to a 30.

Good luck with it. Cheers

[CNs]

Is this the 14ft model or the 16ft?

I had a 14 ft tiller lowe angler with a 30hp. It ran close to 30mph(GPS) one person no tackle. If the max rated HP is 30 you are underpowered.

With over 500lbs of people and tackle you are doing the max or close to it. A new prop may help

If it is the 16ft model then you really need a bigger motor and smaller friends.

[toned]

14 foot

I am just surprised because my older boat (older princecraft pro series) with a 15HP did 23mph with me alone, about 20 with me and the same buddy...it was for sure a lighter boat, but this one has an extra 5HP

Thanks again guys, it may just be what she's good for with the 20HP, but worth investigating further I guess

[Roblin]

Not a big enough motor. I had a Legend and I believe the problem is weight distribution. Mine needed a bigger motor to make it go.

[Mike M]

You need a smaller buddy.

[campnfish]

Does the boat plane with you and your friend + tackle in it?

I'll echo the suggestion of looking at the weight distribution. Get the weight closer to the back of the boat so you can get the nose out of the water. If the nose stays high, you don't have enough power to get it 'up' and planed. At this point with the nose high, you could try and shift some of the weight back to the front, the idea being you want to be on top of the water rather than in it, pushing a huge wake.

[CNs]

I should have asked is this speed GPS based?

[scarkner]

Is this your first four-stroke? If so, that could also be why the motor doesn't sound "right" to you since you only get fire in the cylinders at half the rate of a two-stroke. So even at the same RPM, a four-stroke outboard just doesn't have that "waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" sound of two-stroke..

I know in your head everyone is now hearing that classic sound, here, I'll make it for ya...

[jona38]

Are you sure you don't have a high thrust model? Also have you moved the pin around for your manual trim to get the best position for top speed?

[Kerrazy]

I am thinking the trim pin could be an answer too. With all that weight I would adjust the trim pin to help you get up on plane

Kerrazy

[toned]

Does the boat plane with you and your friend + tackle in it?

I'll echo the suggestion of looking at the weight distribution. Get the weight closer to the back of the boat so you can get the nose out of the water. If the nose stays high, you don't have enough power to get it 'up' and planed. At this point with the nose high, you could try and shift some of the weight back to the front, the idea being you want to be on top of the water rather than in it, pushing a huge wake.

no it does not wake
I am going out tomorrow and will try to take a boot alone to see if it will plane with just me

the day it was windy, we tried to have him move around...when I had him at the back, it was doing 8mph...seriously, nose up and not going anywhere...at the front is when it did 11mph

I'll try my buddy moving around tomorrow to see how it does

I should have asked is this speed GPS based?

yes, GPS speed

Is this your first four-stroke? If so, that could also be why the motor doesn't sound "right" to you since you only get fire in the cylinders at half the rate of a two-stroke. So even at the same RPM, a four-stroke outboard just doesn't have that "waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" sound of two-stroke..

I know in your head everyone is now hearing that classic sound, here, I'll make it for ya...

it is my 4 stroke and to be honest, it's the first 4 stroke boat I ride in, so you may totally be right about that

the sound you make is pretty close to the real thing, you should be an online sound man :p

Are you sure you don't have a high thrust model? Also have you moved the pin around for your manual trim to get the best position for top speed?

not sure I am following, can you elaborate? you mean the prop is the high thrust model? or what exactly? and how do I find out?

I will try moving the pin tomorrow, and see how that does

-- ----------------
thanks for the reply everyone, much appreciated!

the buddy I am going with tomorrow is about 80 lbs lighter and has less tackle, so we'll see how it goes...and I'll take it out alone and see how I do solo

[Kerrazy]

I way a svelte 180, but gear is another 50. So I am no help as a fishing buddy. Sorry.
Kerrazy