1981 80HP, Cranks, No Start

[dctucker]

Cranks fine, no start. No spark on any cylinder.

Following the ignition diagnostic path in the Seloc manual I've learned:

Stator in spec.
Trigger in spec.
ignition coils in spec.

Continuity Test, Shift Box Side, Remote Control Harness Connector -Checking continuity on the cable/control box side (male plug), right? Here's where I find problems:
Pin 4 => Pin 7, Switch Off -No Continuity, Seloc says there should be.
Pin 1 => Ignition A (Purple), Switch On -No Continuity, Seloc says there should be.
Pin 1 => Pin 3 Switch On - No Continuity, Seloc says there should be.
So this means the wiring harness between the control box and the engine is bad, correct? Or does it indicate a probem with ignition switch? Or am I checking the wrong end? (should I be checking at the engine (female)side?)

The ignition switch tests all come out Okay according to Seloc. I'm inclined to believe the ignition switch IS okay, as the engine does crank, enricher works, etc.

If I do have to replace the wiring harness connector, should I just replace the switch at the same time?

Thanks for the help!

 

[Laddies]

Re: 1981 80HP, Cranks, No Start

First disconnect the black/yellow wire from the switchbox and ck for spark that will tell if you have a engine or wiring problem, once thats established we can help you from there. I am assuming that this is the right harness for your engine

 

[dctucker]

Re: 1981 80HP, Cranks, No Start

Engine's run reasonably well for 1.5 seasons I've had it, and the harness came with it from the original owner, so yes, I'm pretty sure I've got the right harness! Seloc calls it Type V ignition system with 8-point connector plug.

I'll disconnect the black/yellow, check for spark again and report back.

 

[Laddies]

Re: 1981 80HP, Cranks, No Start

As you may have guessed by now the only manual thats worth the paper it's written on is from Mercury the rest make good toilet paper

 

[dctucker]

Re: 1981 80HP, Cranks, No Start

Okay Laddies,

Went out and spent $7 for a spark tester to be sure... no spark with black & yellow connected, no spark with black & yellow disconnected from the switchbox either.

I did verify in the prior test session that the fuse is good (has continuity).

So, what do you think, wiring or engine side problem?

Bad kill switch possibly??

What's the next test?

 

[dctucker]

Re: 1981 80HP, Cranks, No Start

bump

 

[jtexas]

Re: 1981 80HP, Cranks, No Start

You ruled out the kill switch and the keyswitch when you got no spark with black/yellow disconnected.

If you haven't already, make sure all the connections are tight & clean including ground wires on the engine block, inspect wiring for cracked and missing insulation.

Disconnect the yellow wires from stator to rectifier and try again, if it fires then replace the rectifier.

don't forget to charge the battery.

 

[phatmanmike]

Re: 1981 80HP, Cranks, No Start

do you have 12V at the red terminal on your switch box at all times?

do you have 12V at the white terminal with the key in the ON position.

my 1979 115 had the same problem, turns out my main engine harness had just gotten old and wasnt givving 12v to the white terminal.

use a jumper to test it

 

[dctucker]

Re: 1981 80HP, Cranks, No Start

Thanks guys. I'll check both of those today.

And yes, I'm smart enough to have the battery charged, if nothing else!! (Just ask my wife... about the nothing else!)

Replacing the entire engine harness has crossed my mind, might not be a bad idea. There is some stuff I rewired in the past, as the insulation was rotten and wires were disintegrating.

 

[dctucker]

Re: 1981 80HP, Cranks, No Start

DOH! Left the key on for two weeks, battery is flat. Not sure why that would be... Charging now. Put the control box back together and remounted it. I made sure it was fully charged and on the charger for my last tests!

Will clean up grounds for now, and have a beer while it's charging.

 

[dctucker]

Re: 1981 80HP, Cranks, No Start

jtexas, I think you may have nailed it.

13.2V across the battery terminals after disconnecting the charger. Nothing at the red or white terminals on the switchbox, key on or off. I'm no expert at wiring diagrams, but I'm not sure how there should be, phatmanmike.

Disconnected the 2 yellow/blacks from the stator to the rectifier, cranked, and it tried to fire. Most encouraging sound I've heard from this 'ol beast in several weeks. I'll see if I can pick up a rectifier tomorrow or Saturday and see what happens. Note, those two are 2 of the 3 wires that were most disintegrated when I got this motor. I cut them back as far as I could, heat shrinked the rest, and put new ends on.