50hp top speed?

M

michaelj1978

Seaman

Joined

Jul 8, 2004

Messages

50

• Apr 18, 2005

• #1

I know it will vary from boat to boat but what are normal top speed numbers for a 50hp motor?<br /><br />I had the gps hooked up and got 28.9 over the weekend. Still don't have the tach hooked up yet, will be in the shop this week for that.

 

D

Dhadley

Supreme Mariner

Joined

Feb 4, 2001

Messages

16,978

• Apr 18, 2005

• #2

Re: 50hp top speed?

How fast will it go? I know its hard to believe but -- it'll go wide open!<br /><br />An SST 45 uses a stock 2 cylinder 50 hp powerhead. They run about 80.

 

Chinewalker

Fleet Admiral

Joined

Aug 19, 2001

Messages

8,902

• Apr 18, 2005

• #3

Re: 50hp top speed?

I've driven a 15hp Evinrude at over 50mph (APBA ASH). I've driven some others that at wide open would barely keep up with the current (work barge laden with building supplies). <br /><br />Bottom line is that there is no set speed for a motor in terms of miles per hour. Not even a range of speeds, unless you count somewhere between 1 and 100. Far too many variables to take into account. <br /><br />- Scott

 

G

G DANE

Commander

Joined

Nov 24, 2001

Messages

2,476

• Apr 18, 2005

• #4

Re: 50hp top speed?

On, lets say a 17' runabout, 28,9 is fine with a 50 HP. On Titanic, if it was afloat, a little less.

 

M

michaelj1978

Seaman

Joined

Jul 8, 2004

Messages

50

• Apr 19, 2005

• #5

Re: 50hp top speed?

It's an 18 foot flat bottom aluminum, 12 gallons of gas, 450lbs of people, full cooler, all gear and fully finished interior.

 

D

Dhadley

Supreme Mariner

Joined

Feb 4, 2001

Messages

16,978

• Apr 19, 2005

• #6

Re: 50hp top speed?

What pitch prop?

 

C

chris in va

Chief Petty Officer

Joined

May 4, 2003

Messages

410

• Apr 19, 2005

• #7

Re: 50hp top speed?

I can vouch that a Suzuki 75hp on a 'mini' fiberglass bass boat with 16' length and all the doodads would go about 35mph GPS.

 

Mark42

Fleet Admiral

Joined

Oct 8, 2003

Messages

9,334

• Apr 19, 2005

• #8

Re: 50hp top speed?

I had my 40hp up to 70mph, but that was on the Long Island Expressway. It goes a bit less in the water.

 

Silvertip

Supreme Mariner

Joined

Sep 22, 2003

Messages

28,762

• Apr 19, 2005

• #9

Re: 50hp top speed?

We have no idea (nor do you) if the engine is at its RPM peak at 28.x MPH, and what the current prop pitch is so its impossible to tell if you can squeak out one MPH more or 5 more. I can guarantee at least one MPH increase by throwing either the beer or a passenger overboard. <br />I think you are about at the upper limit for that rig however.

 

M

michaelj1978

Seaman

Joined

Jul 8, 2004

Messages

50

• Apr 19, 2005

• #10

Re: 50hp top speed?

I had a 15 pitch on there and was only getting about 20mph before it started cavitating/ventilating. I have a 19 on there now and top speed is faster as well as it no longer spins up the engine unless I tilt the motor way up. I have no problem at all getting it up on plane and there is no bogging on the motor at any speed. Motor is a 1995 50hp evinrude 2 stroke 2 cylinder oil injected.

 

D

ddaigle

Petty Officer 1st Class

Joined

Feb 9, 2004

Messages

332

• Apr 19, 2005

• #11

Re: 50hp top speed?

I have a flat bottom alum. similar to yours with an old 60hp which is about the same as your newer 50. I run a 15 pitch prop at about 6000 rpm and get about 35 mph with a great holeshot. Sounds like you have set up problems or a bad prop. I would bet that a 19 on that motor is too much prop and while it doesnt sound like its bogging, your top rpm's are probably way low which can be harmful. Post more about your setup-motor height, type of prop, rpm, etc. and some of the experts here can help you out.