Logo

Johnson 50hp model 50ES71 Tachometer

jerry

Member
" I just replaced my 1962 75HP

" I just replaced my 1962 75HP V4AL14 Johnson engine. I cut the electrical cables under the dash, leaving a long enough tail. I replaced above mnotor with a 1971 50HP 50ES71 motor. Motor is running fine. Questions: the original 75 HP had a tach and I want to know what wires I need to connect from the 50hp to the wires going to the tach cut under the dash. Current 50 hp has 13 wires from motor to control box. If I take positive and negative wires from control box and tie to wires under the dash, will this activate my existing volt meter, fishfinder ,lights etc. "
 
"Jerry.... Your old V/4 1962 7

"Jerry.... Your old V/4 1962 75hp Johnson incorporated points, condenser, coil, etc (the old type battery automotive type ignition) and no doubt that tachometer operated off of, and was connected to that ignition system at some point.

Your present engine, a 1971 50hp Johnson, has no points, but rather has a solid state ignition system. Tachometers that associated with that engine operate off of the charging system.

Bottom line is that it is very unlikely that your old tachometer is compatable with your present engine.

Pertaining to the 12 volt supply being applied to various accessories... any 12v supply will do that, but you would be better off if you ran a line from your battery to a fuse panel, then to a switch(s). Running 12v directly from your engine control box to other components, and later on possibly developing a short in one of those components, would blow the main engine fuse. Not a good idea.

Joe
"
 
Back
Top