S.L.O.W. function 150 Evinrude EXEOM 1995

w2much

Lieutenant
Joined
Jun 22, 2005
Messages
1,292
Have pulled my hair out last 2 fishing trips. Same issue last 2 trips. Engine starts and run great in the morning , go 25 to 30 miles running great. Stop on an patty fish for a bit . When I restart the engine it is in SLOW. First off, I did not know it was in SLOW. I thought there was , and there may have been a fuel restriction. Motor will not go over 2500 rpm or so. That means about 7 mph with the wind at my back, fairly calm seas, hot and sunny, sucking two stroke exhaust for the 3 or 4 hour ride in with 2 disappointed passengers. Not a fun trip.Passengers are getting drunk and we troll in as I am in the back messing with fuel lines,running that loud engine, sucking up exhaust, got an ear ache and a head ache. Enough crying. I am fairly adept mechanically I work on small outboards and my own. SLOW function never entered my mind. I thought bad coil?,power pack, water in the tank or fuel restriction.
I will have more questions as I diagnose what is or are the issues here but for now I have these question. In slow when throttled up the motor breaks up, shakes terribly . Runs good up to 2500rpm or so. Could I have simply disconnected the harness plug in the engine and run in at speed ? What exactly is happening in the power pack to limit rpm by way of breaking up and shaking as it does ? Mixes up timing? Weakens the spark.? Thanks in advance for your replies.
 

Wkd179

Seaman Apprentice
Joined
Jun 26, 2013
Messages
44
slow limits rpm to 2500 miss fires the pack. try to find brown wire that goes into the pack and disconnect it. I assume proper champion spark plugs are in it
 

w2much

Lieutenant
Joined
Jun 22, 2005
Messages
1,292
Yes, new ql77jc4, . thank you, will mess with it today.
The brown wire also contains the diode , is that corract ? When the ignition key is turned on I get the beep after system check. That means the warning horn itself is functional correct ?
I did a resistance test from the pin on the red harness plug to the temperature switch connector on the harness. My readings were the same when I switched polarity as per the instructions in the factory manual.. If this diode is bad might this be my issue?
Thanks
 

Wkd179

Seaman Apprentice
Joined
Jun 26, 2013
Messages
44
Yes diode could be causing problem if oil tank is low for example...
 

w2much

Lieutenant
Joined
Jun 22, 2005
Messages
1,292
My diode was definitely bad. So far I have replaced it. Questions of course :
Any known issues which would cause this. ?I understand it is not a common occurrence.
I also realize it is a tiny electrical part in a 23 year old motor. I would like to know before I rewrap the tape on the harness and close it up.
 
Top