electrical demons - 93 PS190

[skiviskaves]

Here's a mc brain teaser for you. I bought a '93 PS190 w/351 carb at the beginning of the summer and have been chasing a rough running issue combined with some electrical anomalies. I installed a rebuilt carb just to get the boat running consistently, followed by fuel filter, water separator, plugs, wires, rotor, cap, and new battery. I had a strange power draw of about .5 volts from the battery, even with the key off...installed a cutoff switch so the battery isn't drawing all the time.
At this point the boat is running pretty well, but is extremely cold blooded and takes a long time to warm up and idle on it's own. Once warm the boat likes to bog down out of the hole, and sometimes dies on "hit it!". If I ease into it the boat will take off well, and once the boat is out of the water it runs great.
Here's where it gets interesting. I started thinking my issue was the electric choke, or a faulty electric choke. I checked with a meter and only have 9 Volts going to the electric choke instead of 12. Then, last time I turned the key (but didn't crank the motor over), the ignition coil started whining loudly. And then I watched the electric choke open up quickly...motor not running. I could feel energy clicking through the coil wire to the distributer, if that makes sense. The coil kept screaming until I turned the key off.
One other weird electrical thing, the hour meter spins off an hour about ever 10 minutes. I probably put 30 hours on the boat over the summer, the meter turned about 300 hours.
Based on the noise from the coil I am replacing that next, hoping that maybe a short in the coil is causing my other electrical issues. Would that make sense? Anybody seen anything like this before? Any ideas?
Thanks in advance!!!

[93Prostar190]

Don’t forget all grounds you find, keep us posted, we should be able to help out.


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[thatsmrmastercraft]

You definitely have some strange electrical things going on there. I agree on replacing the coil. You also need to track down the bad connections you have. Start with all the battery connections, including the block ground. Remove each one and clean with a wire brush. Is your ballast resistor still installed? That could be a partial source of the reduced voltage to the coil.


Custom wheel and tire packages
Rebuilding Holley Carbs $289
Rebuilt complete Holley Carbs $425

[EricB]

Measure the resistance across the coil + and - terminals. I'm not sure what it should be, but I'm sure somebody has it somewhere here. It may even be printed on the coil case.

In the situation of the choke voltage, that reading is dependent on how the DVOM leads are hooked up, and whether or not you unplugged the choke wire to test for voltage. How did you test?

[skiviskaves]

Originally Posted by EricB

Measure the resistance across the coil + and - terminals. I'm not sure what it should be, but I'm sure somebody has it somewhere here. It may even be printed on the coil case.

In the situation of the choke voltage, that reading is dependent on how the DVOM leads are hooked up, and whether or not you unplugged the choke wire to test for voltage. How did you test?

Just put a voltmeter to the hot wire on the choke, ground to ground, key on. It read 9V both connected and disconnected from choke.

[waterlogged882]

Originally Posted by skiviskaves

One other weird electrical thing, the hour meter spins off an hour about ever 10 minutes. I probably put 30 hours on the boat over the summer, the meter turned about 300 hours.

Based on the noise from the coil I am replacing that next, hoping that maybe a short in the coil is causing my other electrical issues.

There is a thread here somewhere about the same scenario on the hour meter. Can't remember the outcome but I think the thread provided cause and resolution.

I have the same engine / year model. Mine was not running as well as I wanted and I was on the brink of a new carb (may still get a new one). Had the same characteristics that you describe aside from the electrical gremlins. I added a new and hotter Flamethrower II coil ($46 from Summit Racing) and replaced the OEM EI module ($130 from Summit Racing), Now runs like a well-oiled Singer sewing machine.

$0.02

.

[thatsmrmastercraft]

Originally Posted by waterlogged882

There is a thread here somewhere about the same scenario on the hour meter. Can't remember the outcome but I think the thread provided cause and resolution.

I have the same engine / year model. Mine was not running as well as I wanted and I was on the brink of a new carb (may still get a new one). Had the same characteristics that you describe aside from the electrical gremlins. I added a new and hotter Flamethrower II coil ($46 from Summit Racing) and replaced the OEM EI module ($130 from Summit Racing), Now runs like a well-oiled Singer sewing machine.

$0.02

.

A hot spark goes a long way and is usually the first thing to suffer from reduced voltage, but not necessarily the first thing noticed.

New carb instead of a rebuild.....you're killing me!!!


Custom wheel and tire packages
Rebuilding Holley Carbs $289
Rebuilt complete Holley Carbs $425

[windsurfnut]

On my 88 Prostar, same engine, I had some weird electrical issues that I tracked down to the wire harness. The black rubber harness connector that is at the rear of the engine, shortly before the connection block was bad and had some voltage drain and connectivity issues. I cut it out and soldered new ring terminals to the wires and went straight onto the connection block. never had another voltage problem, and boat never cut out again.
I found it by squeezing it while the engine was running and I was able to simulate the engine cutting out.
After that my voltage gauge showed strong voltage too.
Hope this helps.

[JimN]

Originally Posted by skiviskaves

Here's a mc brain teaser for you. I bought a '93 PS190 w/351 carb at the beginning of the summer and have been chasing a rough running issue combined with some electrical anomalies. I installed a rebuilt carb just to get the boat running consistently, followed by fuel filter, water separator, plugs, wires, rotor, cap, and new battery. I had a strange power draw of about .5 volts from the battery, even with the key off...installed a cutoff switch so the battery isn't drawing all the time.
At this point the boat is running pretty well, but is extremely cold blooded and takes a long time to warm up and idle on it's own. Once warm the boat likes to bog down out of the hole, and sometimes dies on "hit it!". If I ease into it the boat will take off well, and once the boat is out of the water it runs great.
Here's where it gets interesting. I started thinking my issue was the electric choke, or a faulty electric choke. I checked with a meter and only have 9 Volts going to the electric choke instead of 12. Then, last time I turned the key (but didn't crank the motor over), the ignition coil started whining loudly. And then I watched the electric choke open up quickly...motor not running. I could feel energy clicking through the coil wire to the distributer, if that makes sense. The coil kept screaming until I turned the key off.
One other weird electrical thing, the hour meter spins off an hour about ever 10 minutes. I probably put 30 hours on the boat over the summer, the meter turned about 300 hours.
Based on the noise from the coil I am replacing that next, hoping that maybe a short in the coil is causing my other electrical issues. Would that make sense? Anybody seen anything like this before? Any ideas?
Thanks in advance!!!

Clean ALL of the grounding points on the battery, dash harness, boat plug, solenoids, engine block, the base of the distributor- EVERYTHING. The Distributor grounds through its base and if that's dirty/funky, you will have ignition issues.

[skiviskaves]

The boat is 3 hrs from home, basically in the middle of nowhere, heading to see it and troubleshoot this weekend. I'm thinking I should bring a new coil with...not sure what is on there...it's red. I'm looking at a Pertronix 45001 Flame-Thrower II Coil at a nearby store, .6 OHM internal resistance, Oil filed, 45,000 Volt. Wanted to confirm with the MC gurus that this coil will work with my boat and stock distributer setup? Did the '93 351 boats have an external resistor? Any input is appreciated. Thanks!