Starts fine stalls won't restart

[Chunkz]

Hello I have a 1999 Johnson ocean runner 175 it starts up fine idles for 5 mins then stalls it restarts every time but stalls seconds after. Fuel tank lines and separator are new and did not fix. Engine has 33 hours on rebuild. I also noticed when I am doing a wash down if I turn the key off it remains running but the tone changes drastically like it's in limp mode. Any suggestions

[Joe Reeves]

Turning key OFF, engine drops rpms but stays running = kill circuit is being applied only to one bank of cylinders.

This could be a faulty powerpack BUT is usually due to one kill wire to the powerpack having a break in it, a poor pin/socket connection.

The black/yellow wire at the ignition switch (kill circuit) runs back to the engine, and there it splits into two black/yellow wires, both of which are normally grounded when the key is in the off position.
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(Ignition Kill Circuit)
(J. Reeves)

A Black wire (ground) should lead from the powerhead to the powerpack. There will also be a Black/Yellow wire leading from the powerpack to a raised "M" terminal of the ignition switch. To complete the circuit, there will be a Black wire from the other "M" terminal of the ignition switch to ground.

When the key is in the OFF position = The two "M" terminals are connected,. effectively shorting/killing the ignition.

When the key in ON position = The two "M" terminals are not connected and the ignition is engaged.

[Chunkz]

*** that was extremely informative and makes very good sense i will check connections and post findings this week. Thank you so much Could this also be why the engine stalls ?

[Joe Reeves]

*** that was extremely informative and makes very good sense i will check connections and post findings this week. Thank you so much Could this also be why the engine stalls ?

Possible but not likely. Could be idling too slow, or running lean (carburetor slightly clogged/gummed), or failing fuel pump.

When running to test pump, simply pump fuel primer bulb constantly, acting as a manual fuel pump. If that cures the stalling = air/fuel leak somewhere, fuel restriction, failing pump.

If the fuel primer bulb is slow snapping back to it original position or has a tendency to go flat somewhat when running, suspect a fuel restriction.

[Chunkz]

Ok so turns out I have some serious problems.

Fuel bowls warped, fuel inlet cracked, power pack coils plugs wires and optical sensor all replaced. Still won't turn off. Found corroded splice in harness repaired wires. All good on the water after I fixed all these issues and the fuel pump took a crap. Are these just the crappiest engines on the market? Should I replace the rectifier and stator too? I'm replacing everything else and yes I have been diagnosing but everything I replaced has crapped Out so far this year.