I have a new 2019 115 E-Tec on a lightweight 17 ft center console. The motor runs perfect except around 4000 rpm it tends to surge. It's very slight and only drops a couple hundred rpm, but definitely doesn't feel right. It does this in brief spurts. The best way I can describe it is it feels like you hit some weeds, then the weeds clear off. It is very suttle.
05-13-2019 08:31 - edited 05-14-2019 08:20
What is the complete model number on your motor?
What speed is the boat at WOT and is the tach digital or an analog (needle) style?
If the surge is only at about 4000 and it clears up just below and just above that rpm, the chances are it is during the exhaust tuning valve activation. If it continues to surge as you run faster, then it may be a fuel delivery problem and the fuel pump pressures, boat fuel system vacuum, and an air bubble check may be needed and possibly a cylinder balance test.
"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.
This is the exact symptoms I had with my 2007 115 E-tec. I added some starbrite enzyme fuel treatment to my fuel and it cleared it right up. I assume there was either some moisture in the fuel or a dirty injector.