1986 200hp Johnson Doesn't Start After Playing on Water for Few Hours

[stirlingmueller]

This has happened to me twice. I start up the engine in the morning and it runs smooth. Play around on the water for a few hours, starting and stopping the engine a dozen times. Then. Doesn't start. Starter motor is strong, turning the fly wheel, but engine doesn't turn over.

I replaced the batteries
Verified the batteries are getting charged by the stator
I've checked for spark voltage and there is
Checked bulb pressure and I have it
Recently replaced fuel pump so I know it's good

When I get the boat home to clean it, it runs fine. It's only when the boat is hot and in the water. Last time this happened, I sat on the water for 2 hours waiting for the engine to cool. But it took 3 hours while the boat was being towed back for it to start up again. Some people mention vapor lock. And in fact I notice the second time I had to re-pump my fuel bulb because the fuel line was full of air. But to no avail. I even tilted the engine a few times to try and cycle out the fuel and air.

Anyway. I could use some help.

[Joe Reeves]

Check the stator under the flywheel to see if either of the two black coils are melting down (beginning of the ignition system), and if so, replace it.

A failing cold stator may,function properly BUT when HOT, as in standing and all that powerhead heat racing up to the flywheel area, the stator will not provide the necessary AC voltage to the powerpack capacitor... resulting in weak, erratic, and eventually no ignition.

[stirlingmueller]

Okay. I'll do that. Yesterday I started up the engine and noted that the idle RPM on the starboard bank of cylinders was 840 and on the port side was 1700 on two and 1400 on one of the cylinders. I also noticed a bulge on one of the power packs. So I think you're onto something with it being an electrical issue.

My question is what is the cause and what is the effect.

I was looking at the timing and the idle timing was 2 deg BTCD. I can't find the timing requirement for a 1986 but for a 1987 it's 6 deg ATCD. Are they the same? If the timing is off would it cause an overheating issue which in turn would damage my stator?

How can I tell if my temp sensors work?

[Joe Reeves]

Re-read my original reply. Don't be flying off in all different directions.