05-03-2012 12:25 - edited 05-03-2012 12:43
I've got a brand new 25hp E-TEC long shaft on a HD15DB Xpress. I can only get 28MPH unloaded and 25MPH loaded with two people weighing 425 total, plus ice chest, rods, 2 15lb anchors, 3 tackle boxes. Motor has less than 3 gallons of gas through it. Does this motor get faster after break in time? Is the ECU holding back on full RPM until break in has been reached? Motor has 13p powertech stainless prop.
i"m not familiar with your boat but close to 30mph with a light load being pushed by 25hp is not too bad.
The most importantt thing is that the motor is turning the proper rpm, especially with the load of people, gas, and gear. Get with your dealer who may ride with you using the laptop to check rpm if you do not have an accurate tachometer in the boat.
The factory recommends an optimum rpm range of 5400-5750 for the 2012 25hp E-TEC. That means your motor should turn about 5800 rpm with a light load and turn more than 5400 rpm fully loaded. The top redline rpm is 6000. You can also experiment the engine mounting height to gain rpm and speed. A stainless steel propeller will also give the better speeds than an aluminum one.
"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.