'71 60hp Evinrude - freaky electrical

JRuggiero

Cadet
Joined
Jun 17, 2004
Messages
23
Speedy summary:<br /><br />Bought boat and motor - took to river. Will tweaking carbs, idling at the dock for 5-7 minutes, hydro-electric shift popped in forward and never shifted again. Stupidly, I took it out for one more spin at WOT and got a burning smell.<br /><br />Neutral shift solenoid is toast - got perfect continuity between green lead and case ground. When I ran WOT, that short toasted my rectifier (the burning smell).<br /><br />Clipper tested shot, permenantly removed it. Amplifier had been replaced recently by previous owner (still good). Shift diode tests good. Replacing burned rectifier.<br /><br />Discovered ignition switch is magneto type. Purple/green shift 12v wiring was wired to one of the M posts by previous owner. Also, blocking diode had been removed from the shift box. Gearcase must have been getting only 12v from the diode system running off stator wires.<br /><br />Okay, all that being said (and that is the abbreviated version!), why did the shift solenoid blow. Any connection to improper wiring at the ignition switch? I know that the power the solenoids were receiving was not part of the rectified 12v circuit, but the diode on the powerhead is similar design to a rectifier.<br /><br />Anything I should be aware of or got wrong?? Thanks!
 

JRuggiero

Cadet
Joined
Jun 17, 2004
Messages
23
Re: '71 60hp Evinrude - freaky electrical

bump<br /><br />No takers? Guess I can't blame you... :)
 

mrc

Petty Officer 2nd Class
Joined
Dec 8, 2001
Messages
149
Re: '71 60hp Evinrude - freaky electrical

It was probably just the solinoids time to go. It's just a coil of magnet wire, not much that you can do to kill it short of applying gross overvoltage which does not seem too likely.
 

JRuggiero

Cadet
Joined
Jun 17, 2004
Messages
23
Re: '71 60hp Evinrude - freaky electrical

Thanks mrc3. I put in my new rectifier, checked voltages - everything looks ok. I hope that the solenoid just decidied to go on its own, I hate leaving electrical issues unsolved, but I don't think there is any other explanation for that one.<br /><br />I do need to wire in a new diode up in the control box. Now that my ignition switch is properly wired, I cannot shut down the motor! The shift diode connected to the stator now provides voltage to the "on" position even with the switch off (no diode up front to stop it) which in turn powers the amplifier which keeps the motor running which poweres the diode on the stator, etc etc etc...<br /><br />Any recommendations on what kind of diode I should use there?
 

mrc

Petty Officer 2nd Class
Joined
Dec 8, 2001
Messages
149
Re: '71 60hp Evinrude - freaky electrical

I just used the largest diode I could find at radio shack... It's not real critical... 50piv or more, probably at least a 3 amp rating.
 
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