1991 70hp VRO Evinrude wont start but cranks over

sonic5208

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a bit of a wierd one. Last time i had the boat out it was hard to start but did eventually start. Was just winterizing this weekend and could not get it started. The engine cranks fine but will just not fire up. The plugs were not really wet (as i would expect from trying to start) but the bulb was hard ( I also tried diconecting the gas line where it goes into the engine and got that little spray so fuel supply was there) and the carbs had gas (i know that because i eventually gave up starting and drained the carbs and just sprayed fogging oil in the cylinders to winterize and changed gear oil etc.). I noticed oil or gas mixed in with the water comming down the driveway from the water ears to start the motor on the driveway. I tried checking for spark but could not get a spark ( i took another plug and grounded to the motor). Verrrryyy confused. i did check that there was power to the 3 red wires going to the terminalls near the coil. can anyone make any suggestions.
 

sonic5208

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Re: 1991 70hp VRO Evinrude wont start but cranks over

Anyone with ideas at where to start
 

mrcj001

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Re: 1991 70hp VRO Evinrude wont start but cranks over

Remove the black/yellow wire from the power pack , then turn the engine over using the key switch. If you get spark, the key switch maybe bad. If you still dont get spark then the power pack could be bad.
 

kfa4303

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Re: 1991 70hp VRO Evinrude wont start but cranks over

I'm no pro, but I have a few basic ideas that may help. I'm assuming your battery is well charged and that you can get juice to the motor per your satement that the motor turns over, but won't fire. However, to be sure you really don't have spark to the plugs, it may be worth it to get a new set of plugs (never a bad idea and fairly cheap) and install them just to be sure. You can also try a spark plug tester for about $6 from the auto parts store. They're cheap and handy tool. If it lights up (jumps a 3/8" gap) when you crank the motor you know that the spark plug wires are ok and the plugs are getting juice in which case it may be a fuel delivery system issue, in which case you may want to try cleaning the fuel lines/carbs well just to eliminate any obvious problems.
If the new plugs/tester don't get spark then you know that it has to be something in the ignition system. I believe, that means taking off the flywheel, and diging into the guts a bit at which point I'm still a rookie. I did get an old 60's Johnson up and running again, but I'm not sure if your late model engine uses similar ignition technology (I don't think so). I hope this helps a bit. Just basic suggestions.
 

sonic5208

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Re: 1991 70hp VRO Evinrude wont start but cranks over

i am thinking maybe the key switch because it is a bit sticky but i thought if it was cranking the engine and when i turn it to on power goes to the coil that it would be ok.
 

sonic5208

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Re: 1991 70hp VRO Evinrude wont start but cranks over

i also sprayed a bit of graphit lube in the key switch because it is sticky i wonder if that's what it is.
 

patrick4266

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Re: 1991 70hp VRO Evinrude wont start but cranks over

I have the exact same motor. Try unplugging the big red plug at the motor and jumping the solanoid. See if you get spark then.
 

sonic5208

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Re: 1991 70hp VRO Evinrude wont start but cranks over

can you explain that one what do you mean jump the selonoid
 

sonic5208

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Re: 1991 70hp VRO Evinrude wont start but cranks over

anyone have a wiring diagram. Also not sure what is meant by jumping the selanoid. Which wires? what should i expect.
 

mav6759

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Re: 1991 70hp VRO Evinrude wont start but cranks over

I may have a wiring diagram. Just got a new repair manual and i know it covers that year. Just didn't have time cover all of it. It on disk, so I may be able to download the manual to you. let me know if I can help..

Mav
 

sonic5208

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Re: 1991 70hp VRO Evinrude wont start but cranks over

I tested the ignition switch and it's fine. I tried starting it again and same thing cranks over but no go. should plugs be getting soaked because it doesn't look like they are all that wet. i am getting fuel mixture running down the driveway. Took a plug out and grounded to the head and no spark. Is there a relay or fuse?what else can i check.
 
D

DJ

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Re: 1991 70hp VRO Evinrude wont start but cranks over

Two things.

1. Is the Safety LANYARD connected to the control box??? That is one of those "DUH" moments. Don't be afraid, all of of us have missed that one.;)

2, BIG RED plug (under hood). Give it a couple twists. If that solves it, you n eed to adress those connections.
 

jtexas

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Re: 1991 70hp VRO Evinrude wont start but cranks over

sonic,
the black/yellow wire is the kill circuit: turning the keyswitch "off" connects the kill wire to ground, short-circuiting the powerpack, shutting off spark and killing the motor. The lube you sprayed into the keyswitch probably isn't at fault, but the "stickiness" might be a clue -- if the kill wire post is shorted to the ground post inside the switch, it'll prevent the ignition from sparking.

Ruling out a fault in the kill wire is the first step to troubleshooting a no-spark condition.

Disconnecting it at the powerpack takes it completely out of the picture, so if you get spark like that, then you know that either the keyswitch or kill switch are faulty, or else there's a wiring fault in the harness.

Unplugging the wiring harness accomplishes the same purpose, but doesn't rule out a wiring fault on the powerhead (look for burned/missing/chafed insulation where the black/yellow wire might come in contact with cylinder head). Also you can't use the keyswitch to crank the motor. Solenoid has 4 posts, two large (one leads to battery, the other to starter motor), and two small (one leads to keyswitch, the other has a black ground wire attached to the cylinder head). Touching a jumper wire to the large post leading to the battery, and the small post leading to keyswitch will actuate the solenoid and spin the starter. You'll probably see some sparks.

Note that if the motor starts with the kill circuit disabled, you'll have to flood it to shut it off by activating the choke manually.

But before you go to all that trouble, make sure it's a spark issue and not a "spark plug" issue. Get an inline spark tester (less than $10 at autozone), set the gap for 7/16", clip it to the cylinder head, and look for spark while turning the engine over with the key.

and first, I'd do what DJ says......................
 

sonic5208

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Re: 1991 70hp VRO Evinrude wont start but cranks over

ok will try. Yes the laniard is the first think i checked because i have done that before. :eek: I will make sure the red plug is good then i guess i should test the power pack. i did the thing with black yellow and nothing.
 
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