72 evinrude 50 hp won't start, need advice

Hello! I'm hoping you guys can give me some direction here. On my boat I have a 72 evinrude 50 HP lark. This is on our first boat and honestly I didn't know a lot about them when we bought it. Anyway, it ran pretty well for a while - guy we got it from said the carbs had been cleaned within the last year, had good compression, and new water pump put in recently but it wouldn't go in reverse (don't know if that has to do with current issue but figured good to know).

It ran pretty well several times out and then the last time it ran really the best it has ever, just great - until we stopped to fish for a while. Went to restart it and it kept trying to turn over and over, even without the key in it, and I had to pull the battery to get it to quit. Got myself the original manual and started trying things. At the time it happened I thought maybe the ignition was broke and replaced that, didn't help. Since I've replaced the solenoid, starter, rectifier, put in new spark plugs, and new ignition coils. It turns over but its not firing. I should mention it doesn't have a neutral safety switch, it looks like it previously was rewired and they apparently bypassed it. The only thing I can think of to try replacing now is the power pack - but wanted to check with you all to see if you had any ideas about a next step, all these new parts are killing me lol. Thanks so much for your thoughts!!

Jason

Re: 72 evinrude 50 hp won't start, need advice

Disconnect the black/yellow wire from the power pack and see what happens. This eliminates the boat wiring harness and if it starts you'll have to manually choke it to shut it off.

Re: 72 evinrude 50 hp won't start, need advice

Hi Jason and welcome to the forum.
You need three basics for the engine to run, compression, fuel and ignition. You need to find out if one of these is missing. For the time being we will assume that you have compression. To see if you have spark, put a screw driver (with an insulated handle) into the end of each spark plug wire in turn. Hold the screw driver blade 1/4" from the engine block and have some one crank the engine. If you have spark, pull the spark plugs and see if there is fuel on them.

Re: 72 evinrude 50 hp won't start, need advice

OK! We tried the screwdriver, no spark. Then pulled the black/yellow on the power pack and it did start. So, need a new power pack right? I was just excited to hear it actually start lol!

Re: 72 evinrude 50 hp won't start, need advice

NO!! You need to check all the black/yellow wiring in the boat plus your ign sw. Something is grounding out the pack. Normally the black/yellow wire grounds out the pack to shut it off.

Re: 72 evinrude 50 hp won't start, need advice

Hi all - know it's been a while! Thank you all so much for your advice. It turns out it in fact it was the wiring. I got it all fixed and it was working absolutely beautifully - for a while. Then she stranded us again. Went across the river, shut it off to fish, went to restart and nothing. It wouldn't even turn over, didn't make a sound. Tried everything I could think of but nothing, had to be towed back. We thought maybe the battery was the problem, so tested it and it was shot, replaced that. But now, starts up great, shut it off and try to restart, nothing. Battery totally drains. Anything obvious that could be draining it isn't on (like fish finder, lights) so I'm kind of stumped as to next step. Any thoughts? Something has to be draining this but I have no idea what.

Re: 72 evinrude 50 hp won't start, need advice

Hey all - several people have suggested it might be the stator, so with engine running, using AC volt meter between common ground and yellow stator lead getting 2.6 volts - should be getting 12 volts, right? And rectifier checks okay.