75hp ETEC rpm help

CJScott · ‎10-08-2018

Hello all,

Trying to figure out if my problem is my prop or something else. 2015 75hp ETEC on a 2105 SEAARK RXV 186. Boat is a standard aluminum mod-v 18.5' w/ 15 deg hull like many other on the market (G3, tracker, lowe, etc.). Boat has always run around 1000 rpm below target since new. Had a Power Tech RED 13.25x16p when purchased. Recently ran a Turning Point Mach 4 13.5x15p. Both produced rpms around 4100-4200 depending on trim. The boat does handle better with the 4 blade as it is stern heavy. Have tried raising motor height to the point of exsessive slip with little change. Boat speed is around 33-34mph which seems right for an 18' w/ a 75. So, is this a prop issue or possible something else? By all accounts from BRP the engine should have no problem turning both of these props close to the target RPM range of 5000-5500. Any suggestions would be appriciated.

Thanks.

Rickmcd53 · ‎08-20-2017

Props are not my specality, I have only used the BRP or Solas props. You dropped from 16p to 15p but went up in diameter and added a blade so probably ended up with equal engine loads. I would suggest trying a 3 blade 15 pitch. Your engine should be propped to turn 5200 rpm

BluewaterBill · ‎07-14-2011

First have your dealer check out your motor, the fuel pressures, and do a cylinder drop test using the Evinrude diagnostics software and check the tach accuracy. then try different props.

"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.

75hp ETEC rpm help

Re: 75hp ETEC rpm help

Re: 75hp ETEC rpm help