I just got a 1972 100HP Evinrude what do I need to do to it? (It has a few issues.)

[rs2k]

Hello everyone!

I am very familiar with large two stroke engines. I have owned a few light two stroke airplanes, but I have never owned a two stroke boat engine. I would like to know what things I should do to an unknown outboard engine before I use it on a lake. I would eventually like to take this engine and the boat it is propelling a short ways out into the ocean so I want to get it as reliable as I can. The model number is 100293.

Overall the engine looks and sounds good but it has a few issues. The starter is bad so I had to hand crank it with a rope. With a little bit of starting fluid and a good hard crank it fired right up. It sounded very good but a few visual things worry me about it. I hooked up an engine flusher to run water through it. Both exhaust and water come out of the prop shaft. Is that normal? A little water also comes out of part of a seam that runs around the circumference of the engines lower half about halfway up.

I took the starter apart and the armature has a melted spot near the brushes. This melted spot caused damaged to the brushes. Can this be rebuilt or will I just need a new starter? The engine will not charge the battery either. I was told it had a bad power pack. The person I bought the boat from said it had a bad power pack and that they just used a deep cycle battery to start the engine and then run the ignition. I would like to get this fixed.

 

[tashasdaddy]

Re: I just got a 1970 100HP Evinrude what do I need to do to it? (It has a few issues

Re: I just got a 1970 100HP Evinrude what do I need to do to it? (It has a few issues

charging is the recitfier, bad power pack it would not fire. you are going to need a new stater. low battery ususally is the cause for the melt down, not enough power to turn the motor over. you can try a starter/alternator shop with it, but i doubt they will fix it. here are is some good info. check your compression, and spark on all 4.
read this: http://forums.iboats.com/showthread.php?t=158086

Hydro Electric Shift)
(J. Reeves)

The shifting setup of the lower unit is what's called a "Hydro Electric Shift", which is quite complex consisting of voltage being applied to solenoids in the lower unit which in turn change oil passages via a oil pump that supplies various pressure on a spring loaded shifter dog. The wires leading to the lower unit (at the powerhead) are "Green" and "Blue". The engine must be running or cranking over in order to shift out of forward gear.

You CAN NOT use HI VIS lube in that lower unit. You MUST USE what OMC calls "Premium Blend" lube, commonly called "Type C". (A thinner lube)

In neutral, you need 12v to the "Green" wire.
In reverse, you need 12v to both wires, the "Green" one and the "Blue" one.
In forward, there should be no voltage to either wire. (The spring loaded shifter dog forces the unit into forward gear)

To check the lower unit for proper shifting to make sure you have no trouble there, remove the spark plugs to avoid problems and to allow a higher cranking speed.

This next step eliminates the actual shift switch in case problems may exist there.... Disconnect the blue & green wires at the knife connectors (the rubber insulated boots) leading to the lower unit at the powerhead, then using jumpers, take voltage direct from the starter solenoid to apply voltage to the "Green" wire for neutral, then both wires 'Green" & "Blue" for reverse (Remember the engine must be cranking over in order to shift).
With no voltage applied, the unit should be in forward. No need for a ground jumper... the lower unit's already grounded. You may crank the engine with the key switch or by energizing the starter solenoid with a jumper wire.

this is good also: http://forums.iboats.com/showthread.php?t=268201

 

[rs2k]

Re: I just got a 1972 100HP Evinrude what do I need to do to it? (It has a few issues

Thanks for the great info. I don't think it has any shifting problems. It started in neutral just fine and seemed to shift properly when I ran it. Is the rectifier special or can I use a generic rectifier?

 

[tashasdaddy]

Re: I just got a 1972 100HP Evinrude what do I need to do to it? (It has a few issues

oem rectifier part # 580841, or 0582307,0582399,0583408 or this is the aftermarket rectifier http://www.iboats.com/mall/partfind...d_poid=109227&gd_row=209&**********=747188692

 

[rs2k]

Re: I just got a 1972 100HP Evinrude what do I need to do to it? (It has a few issues

Thanks for the info. I'll get one and see what happens. Wouldn't any rectifier than can handle 14 volts at 10 amps work, though? All it does is turn AC voltage into DC, right?