Evinrude E-NATION, for those dedicated to water, power, fishing and fun
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Mate
Posts: 2
Registered: ‎03-05-2016
Accepted Solution

Can't reach top speed

Hi all. I have a 1989 21 foot HydraSports dual console fiberglass sport fisherman, model Vector 2000 DC, with a 2000 Evinrude 150 hp, 2 stroke motor. I can not get top speed from it, going only 15 mph, per GPS reading, at 5000 rpm's. The motor runs great, with no misses and gets on plane, with the help of a whale tail, mounted to the lower unit . I am getting full throttle from the controls to the carbs. I have a stainless 3 blade, 14 1/2 X 15 prop on it. I thought I solved the problem, by having the prop rehubbed and balanced. I also changed the water separator / fuel filter and run fresh gas, with Techron additive, by Chevron. I have pressure in the in line rubber bulb to the motor. I am perplexed over this and out of ideas, to get top speed. A friend of mine, has a similar sized boat, with a 150 Johnson on it and it does almost 40 mph. Any help on this, will be greatly appreciated! Thanks, Freddy. phillyheat1@yahoo.com
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Admiral
Posts: 8,326
Registered: ‎07-14-2011

Re: Can't reach top speed

[ Edited ]

 

 

Something is wrong with your numbers.  5000 rpm on your motor turning a 15" prop has a theoretical top speed (calculated) of 38 mph. With an average of 10% prop slippage, you should be running about 34-35mph with those numbers. If I remember correctly that boat ran well with a 17" SST prop with an rpm slightly above 5000 when new.

 

Clearly your tach or gps is wrong or your prop hub is slipping badly.  Run along side another boat with a known good gps or use a speed app from your phone to check the actual mph. If that checks out, substitute a known good tachometer for comparison. If that checks out, better find a new prop.

 

This is assuming that your prop blades are like new and it is a genuine Evinrude prop and the boat and motor used to perform much better earlier in its life.  If there are barnacles, seaweed, slime or rough bottom paint on the boat, that would make a big difference in speed as would water trapped in the hull.

 

 

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



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The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Mate
Posts: 2
Registered: ‎03-05-2016

Re: Can't reach top speed

Thanks, Bill. I have a real nice Turbo 14 1/2 X 15, stainless prop, that, as I stated, was recently rehubbed, so I believe there is no slippage . I trailor the boat, so there is no barnacle problem. It's a brand new Garmin GPS, so I know the speed is probably close. My tach may be off, but I believe I have another problem. I may try a 15 X 17 prop. Also, could the motor be too low in the water? I have 4 slots on the motor to adjust the heights it sits in the water, and mine is in the top notch, with three other notches to raise it up. I could raise it up a notch or two, so it's not too deep in the water. Does this sound feasible? Thanks again, Bill, for the response. Freddy
Admiral
Posts: 8,326
Registered: ‎07-14-2011

Re: Can't reach top speed

 

 

 

For most applications, the motor's anti-ventilation plate should be visible running at the top of the water while the boat is at cruise speed or higher and trimmed properly.  Is your anti-ventilation plate about 1 or 2 inches above the bottom of the boat which is about average in a runabout like yours? 

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.