300 etec is slow cranking will not start when cold on one battery need to have both on, "all" for engine to start. 1 battery is brand new the other is load tested good at 800cca. Both batteries have 12.6 -12.7 volts. used voltmeter getting good voltage at all connections in start circuit, measured voltage drop across solenoid posts at .5 volts on one battery, .2 volts on my new battery, engine started but slow,. Is my solenoid going bad?
thanks for any advice
06-12-2018 10:18 - edited 06-13-2018 07:08
Cranking over slowly is from either a weak starter or insufficient amperage from the battery or through faulty cables and connections.
Connect a digital voltmeter to the posts (not the cables) to one battery and use only that battery to attempt to start the motor. If the battery voltage drops below 10 volts while cranking, the battery is either discharged or weak.
If the individual batteries check out at 10 volts, then perform a voltage drop test of both the positive side of the starter and the ground side. Your dealer is best equipped to do this.
"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.