1970 evinrude 85hp, no spark

[beaver]

Hey! I have a 1970 evinrude outboard with electric shift. It appears I have 2 problems.<br />First is I don't have any spark. Second is it appears that the motor is stuck in gear, when you crank the engine the prop spins!?!? I don't know if they are related problems, so I need serious help!! How does the shift system work?<br />I'd appreciate ANY help!

 

[mrc]

Re: 1970 evinrude 85hp, no spark

First suggestion, Pick up the OEM service manual. There is one on sale on ebay right<br />now for the 1970 Vintage 85hp which is very much the same as yours. Think the price<br />is like 7$ + 5$S/H unless somebody else bids against you.<br /><br />The motor you have is electric shift, the default gear is forward.<br /><br />It sounds like it is possible that both your problems are related. First thing to check would<br />be the fuse on the engine. It is either located in an inline fuse holder along the side of the<br />motor by the wiring harness attachment plug, or in a fuse holder next to the terminal strip <br />on the back of the motor (between the spark plugs).<br /><br />If the fuse is blown, the most likely reason why, is deteriorated insulation on the <br />wiring on that electrical panel. Remove and check the amplifier and the rectifier<br />for cracked and worn insulation. Repair with liquid electrical tape followed by real<br />electrical tape. If you dont have the manual handy, make sure to mark where each wire<br />goes on the screw panel before removing the wires.<br /><br />Let us know where this leads you and we will go from there.<br /><br />Mike

 

[beaver]

Re: 1970 evinrude 85hp, no spark

Thanks for the info. I checked that fuse and the wiring around the terminal strip. The fuse is good and the wiring appears fine. There is a new amplifier<br /> however one wire from it to the terminal has been disconnected and tied back. Should this be???

 

[mrc]

Re: 1970 evinrude 85hp, no spark

There is blue, grey, purple and black wires coming off the amplifier.<br />The grey does not appear to be connected to anything.<br />Purple should be +12v when key in start or run position.<br />blue goes to the ignition coil,<br />black goes to the points.<br />The amplifier is also grounded somewhere.<br /><br />Verify that with ignition switch in run position, you get 12v to purple wire of amplifier.<br /><br />As far as shifting stuff goes.<br /><br />Facing the propeller (ie the back of the motor). On the lower right hand side<br />there is three wires that go through a long strip of rubber. Those are knife<br />connections, 2 go to the lower unit, one goes to something else <br />Of the two that go to the lower unit, The dark green wire should be +12v in<br />Neutral and Reverse. The dark blue wire should be +12v in Reverse.<br /><br />BIYC <br /><br />Mike

 

[beaver]

Re: 1970 evinrude 85hp, no spark

Hey!<br />Ok, I checked the amplifier and I have everthing you said. 12 volts on purple.<br />Also I am getting the correct readings on the shift wires but i only have 10 volts- I don't know if this is a problem.<br />I'd appreciate any more suggestions!!!

 

[mrc]

Re: 1970 evinrude 85hp, no spark

Voltage on shift wires with the motor off and in neutral/reverse should be about<br />1.2 Volts less than battery voltage as it has to go through a diode to get there.<br />So 10V looks roughly okay, this means you may have a problem in the lower unit<br />but lets get the engine running first.<br /><br />You say you have a new known good amplifier, so we only have a few things<br />left to check.<br /><br />1) Verify points are working correctly. There is a big black wire that goes<br />from the amplifier (via a pull apart disconnect) to underneith the flywheel.<br /><br />With the ignition switch off, disconnect it and connect an ohmmeter between<br />ground and the points wire (Not the amplifier side).<br /><br />Rotate the flywheel slowly and verify that the resistance goes from infinity to<br />zero four times in one rotation. If not, something happened to the points, and<br />you will have to pull the flywheel.<br /><br />2) If the points are okay, test the resistance of the coil. Primary should be less than<br />1.2 ohms, and the secondary should be near, but less than 3000 ohms.<br />Try cranking the motor in the dark, see if you are arcing somewhere around the<br />coil or under the flywheel (where the distributer is located)<br /><br />If you get to this point and still no go, it's time to suspect the new amplifier.<br />Joe Reeves posted a nice way to test this out with a small 12v light bulb in a <br />much earlier post in this forum.<br /><br />Mike

 

[beaver]

Re: 1970 evinrude 85hp, no spark

Hi Mike<br />I have a black and a blue wire coming out from under the flywheel. The black goes to grnd and the blue goes to the amp. I disconnected the blue and meterd from blue to grnd. As I spun the flywheel slowly the resistance was up and down like a dog's stomache. It never opened consistently. There was always some resistance. I gues I have a point problem!<br />In the meantime, which is the primary and secondary coils, and how do I check the resistence?<br />Sorry if I sound like an idiot but I really don't know much about boat motors!!!<br />Thanks again!<br /><br />Chris

 

[beaver]

Re: 1970 evinrude 85hp, no spark

Hey<br />I pulled the fly wheel, and cleaned the points and rotor. Things are good now when i meter the blue wire but i still have no spark.

 

[mrc]

Re: 1970 evinrude 85hp, no spark

Okay, <br /> So at this point:<br /> 1) Good voltage to amplifier<br /> 2) Good amplifier (assumed)<br /> 3) Points are working<br /><br /> So you are loosing spark between the amplifier and the plugs. <br /> In that path is the coil, the HV wires, and the distributer.<br /><br /> I would suggest checking the continuity for HV wire from the coil to the distributer.<br /> The wires unscrew from the distributer cap.<br /><br /> If that wire is okay, check the impedence for the primary and the secondary of the coil.<br /><br /> Try cranking the engine in the dark, watching for sparks, where the coil spark may be<br /> arcing to ground before getting to spark plug.<br /><br />Mike

 

[beaver]

Re: 1970 evinrude 85hp, no spark

I checked the amp with the light, and it appears I have a bad amp!<br />It may take a while for me to find one, but i'll<br />keep you posted!<br />Again, thanks for all your help!!!

 

[mrc]

Re: 1970 evinrude 85hp, no spark

Really unfortunate, You can get them online<br />for $225. ebay almost never has them.<br /><br />I have one with (at least) bad wires.<br /><br />I am debating between dremel tooling the epoxy potting in order to attach new wires, and simply opening the thing up and try to make a circuit<br />diagram for it. I'm sure it would be cheaper than<br />225$ to build one.<br /><br />PS, anybody have this circuit already diagramed?<br /><br />Mike