1972 50 hp evinrude lark w/ hydro shift trouble shooting

chris0061

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Hello, I had posted a couple days ago about thoughts on price on this engine but since I bought it now I need to get it running. It came with one coil off and the man said it just died one day so I'm assuming they were going to try and fix it then he got sick and it just sat. My compression gauge read 180 lbs on both cyl. I thought it was high but my gauge might be off. they were even and that's what I like. Ive got a DVA tester and have gotten older mercs running. This is the first omc I have worked on, I run one on my jon but never had to work on it. With one coil missing is there any troubleshooting I can do while waiting on the coils to get here? I was concerned about the hydro electric shifting cause I couldn't get it out of gear then I read it stays in gear until it cranks or starts so I drained the lower unit oil. went and got type c oil for that outdrive. moved the remote back to the back of the boat, cranked it over and seen that the prop did not spin while cranking and I could even reach down and turn it by hand like it was in neutral so I think all that is fine. I am not getting any spark to the one coil that remains on the engine and before I quit for tonight I notice the ground wire from the rectifier mount to the block was just hanging on by a thread literally. So should I wait for the coils to come in or should I try to trouble shoot some more????? I am missing the top cover that goes ontop of the shift switch. there is a red fiberglass looking strip with a yello wire riveted to it that is broke. the wire goes to the kill wire on the ignition switch.
 

boobie

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

Go to CDI Electronics.com for trouble shooting procedures. You may want to get a multimeter with a DVA adapter and an open air gap spark tester to trouble shoot it properly.
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

I have the multimeter and the DVA adapter I use a timing light to see if there is spark
 

boobie

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

Sometimes timing lights can lie. With an open air gap spark tester set to the correct spec it gives you a more accurate reading of your ignition systems total output.
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

ok got the air gap spark tester no spark. Started testing and mind you this is with one coil off but the oems for the stater were good but the dva were bad.... how do I test the pack without the stator being hooked up?
 

boobie

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

If the stator output is no good you'll never be able to tell if the pack is bad or not. When checking pack output you check all the way around it IE: stator and timer base outputs. If they check good you can then condem the pack. Is the black/yellow wire disconnected from the pack ??
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

no, I cranked it with it off and it still had no spark so I hooked it back up to run the tests. I also unhooked the two rectifier wires with no luck. The dva did read 120 when I grounded that little wire that was conected to some kind of plexiglass strip to the kill wire terminal on the ignition.
 

boobie

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

Please explain the plexiglas strip or post a pic. The rectifer has nothing to do with the ignition.
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

on my shifter the shifter switch cover is missing. there was a red plexiglass or plastic stip that one broke end was on the cover plate bolt and the other end was broke off but it did not have a hole for the other side cover blolt. I'll go down and take some pics
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

dang pics won't upload
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

just had the wire hanging there and acidently touched it while I was turning the key to crank it over and got one heck of a shock. Bottom line is whatever this wire is it is hooked up with the kill wire on the ignition switch.
 

samo_ott

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

Please post a pic. I have the same engine (I'm pretty sure it's a '72 and it's a Johnson) and don't recall what you are referring to so would also like to see it.
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

Steve you would'nt have a wire diagram for that engine you can send me. looks like they started to put new coils on and the one that is on has the orange lead hooked to the terminal block and the black lead bolted under the coil on a mounting bolt
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

OK, here are the results of the test. Brown stator wire read in specs on resistance and dva. There was one coil hooked up when I got the engine and doing the test I got good dva readings between the white black to ground, which did not have a coil on it and got poor dva readings from black white to ground which did have a coil hooked up to it. I took that coil lead off and got a good dva reading and resistance reading on both to engine ground. I got no reading on dva testing wire to wire. also there may be a short in the black white wire cause every time I hooked the lead up to it I got a spark were that wasn't the case on the white black. also when I touched it I got a shock. the key was in the on position. PS Happy New Years to everyone.
 

chris0061

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Re: 1972 50 hp evinrude lark w/ hydro shift trouble shooting

ok, It turned out to be the trigger. Put one in tonight and fired right off. I did the resistance reading from white black to black white just to see what it would read and it read high, out of specs. Would a bad power pack let the engine run but ruin a trigger in time? also what should I set my ohm meeter at?
 
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