4.3 '87 Fourwinns only starts when the key is let off

[98mystique2]

As bizarre as it sounds the boat only catches when the key is let off. Otherwise it cranks till the battery is dead. Seems to run good otherwise. Only started doing this this year. I'm worried there's some electrical Gremlins starting since I unfortunately stored the boat outside (something I will never do again) this past winter and the top support collapsed so it got waterlogged. Where should I start looking?

 

[GA_Boater]

Welcome aboard.

Turn the key on and check for voltage on the coil while cranking. It should have 12 volts while cranking and it drops when the key is released. I think you will find no voltage to the coil when cranking.

Giving us the serial number helps give better advice.

 

[kenny nunez]

There is a circuit known as the “by-pass” circuit that is the problem. Either the boost solenoid or the main starter solenoid is where the circuit gets the voltage in cranking mode. Just for kicks rig a jumper wire from the + battery to the + side of the coil and turn the key to see it it starts, if it does remove the jumper to turn it off.

 

[alldodge]

Turn the key on and check for voltage on the coil while cranking.

My guess would be a bad key switch

 

[98mystique2]

Giving us the serial number helps give better advice.

Thanks for the info,

Unfortunately that information plackard is worn/broken off
It's got a gm Rochester 2 jet and cobra drive if that helps.

Got a few things to investigate looks like

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[Lou C]

I'd start with the igniton switch, you need a 3 position one with Off, Ignition On and Start. On the back of the switch there will be a B terminal (this gets battery voltage all the time as long as the battery switch is ON, red wire) I for ignition, (this gets power when you turn it to the first notch, purple wire) and S for start, this gets power when you turn the key to start (red/yellow wire). Make sure that the switch provides power as noted. Then after that, the other possible problem area is the assist solenoid which is one of the 3 solenoids mounted on the shift linkage bracket on the starboard side of the engine between the exhaust manifold and the carb.

 

[Lou C]

https://www.crowleymarine.com/1/OMC-...Drive/1987.cfm

It could be any of the ones starting with 432 (in OMC's system the 1st 2 numbers were the displacement in liters, the third was the # of barrels in the carb so 432 = a 4.3 2bbl, 434 = a 4.3 4bbl. The P signifies Power Steering and the M manual steering that should help you narrow it down enough....

https://www.crowleymarine.com/johnson-evinrude/parts/55316.cfm?mdl=FPKQKR

the 3 solenoids are mounted to this, the ones for tilt n trim (one is for up, blue wiring and one is for down, green wiring) are mounted to the bracket facing the carb, the one for the ignition system is mounted on the rear facing end of it. They are identical and you can still get these.

 

[Lou C]

https://forums.iboats.com/forum/eng...outdrives/10773385-4-3l-wiring-diagram-needed

your wiring diagram is in this post...take a look at it, may be helpful

 

[98mystique2]

Welcome aboard.

Turn the key on and check for voltage on the coil while cranking. It should have 12 volts while cranking and it drops when the key is released. I think you will find no voltage to the coil when cranking.

Giving us the serial number helps give better advice.

Found a model number. Dug through some manuals that I got with the boat 432APWXS appears to be the model.

I'm getting like 4-5 volts with the key in the on position and ~6 volts with the key starting it that's going from the positive terminal on the coil to battery negative. Same happens with coil positive to alternator body.

I'd start with the igniton switch, you need a 3 position one with Off, Ignition On and Start. On the back of the switch there will be a B terminal (this gets battery voltage all the time as long as the battery switch is ON, red wire) I for ignition, (this gets power when you turn it to the first notch, purple wire) and S for start, this gets power when you turn the key to start (red/yellow wire). Make sure that the switch provides power as noted. Then after that, the other possible problem area is the assist solenoid which is one of the 3 solenoids mounted on the shift linkage bracket on the starboard side of the engine between the exhaust manifold and the carb.

It is starting so I doubted it was the key switch, I have ~0 ohms from the start to battery + cable when the key is in start and same for on.

I'd looked at the wiring diagram previously when the alternator went bad last year (can't remember if it was over or under charging) but the new alternator had a red and black wire as opposed to the purple and purple/red wire but I went red to red/purple and that seems to be correct based on the old alternator location.
The voltmeter hasn't worked on the boat and neither does the trim gauge, haven't had the time to look into either since the outboard still trims and the battery is getting ~14.5 with the motor on

 

[98mystique2]

Also should probably mention I did do a resistance measurement on the coil and got ~1.4 (1.8 actual on the dmm but just with the leads crossed i had .4) + to - and 8k for secondary to +, so the coil looks ok.

 

[alldodge]

I'm getting like 4-5 volts with the key in the on position and ~6 volts

Then Kenny has your answer, its the wire that goes from the starter to the coil is either missing, not connected or corrosion