Electrial Issues on a 87 Sunsport

[oldsupra]

my boat has the pertronx ingtor and was wired without the balest resistor so the coil became very hot --i called pretronx they said that without the balest it would also over heat the ingtor and the boat will not run rite so i ordered a internaly resisted coil from them and have not had a problem

[csuggs]

I agree! You need that ballast resistor! I switch to electronic ignition, a mallory and used the ballast resistor and it works fine!

Ditto for me except Pertronix Ignitor

[FecalFajita]

Ok, So I got a new coil that is internally resisted. Batteries were fully charged before we took it out, after an hour they didn't have enough juice to start the motor. I also noticed that the voltage gauge never goes above 12v, So I ordered a new alternator. I'm not sure why the batteries are discharging though. I have new battery cables and everything seems to be hooked up right. Is it possible that my old alternator is grounding the system somehow?

[FecalFajita]

Also, what does everyone mean exactly by "bypassing" the resistor?

[knoble]

With just having the key in the on position and the coil gets hot leads me to believe you need a ballast resistor! It reduces your volts to the coil! Check your voltage to the coil. It's easy to check with just a volt meter. Basically if your battery reads 14V while running your positive side of the coil should read ~12V-12.5V but no more, if it does you need a ballast resistor added to the wire.
Start your boat and bring it up to a fast idle, around 1500 RPM. First, record voltage at the battery.
Next, record voltage at the positive side of the coil. For optimum ballast resistance, you should have a 1.0 to 1.5 volt drop at the positive side of the coil. A voltage drop greater than 1.5 volts suggests too much resistance. A voltage drop less than 1.0 volts could burn out the spark module when installed.
Verification of a Ballast Resistance Wire According to Mallory Ignition: The test as specified by the Mallory E-Spark Instructions are very similar to the verbal test offered by Crane Cams tech support, only Mallory suggests that the test be taken at idle, not 1500 RPMs. Here is the test per the E-Spark instruction sheet.
One easy way to find if your vehicle has a loom resistance wire is to test your stock ignition system voltage while the engine is at idle at the COIL (+) terminal. If the measured voltage is within 1-volt of battery voltage, an ignition ballast resistor must be installed in the wire from the ignition switch.

[87SunSportMikeyD]

It seems very very odd to me that you can have fully charged battery and the boat won't start within an hour? Did you check the voltage at the battery when the boat is not starting to be sure it is the batteries' fault? With my alt completly removed I am able to board all day on two fully charged batteries they dont seem to get low at all. Good luck with that...

[FecalFajita]

So I put the new alternator on today. It pushes 13.8v at idle and 14.6v above idle. Awesome!

If I try to use the key to start the motor, It blows the circuit breaker. So I had to start the motor by shorting the starter solenoid, So it looks like I blew the solenoid, even though I just replaced it.

Readings across the coil (from positive to negative) when the motor is off reads the same as the batteries. However, when the motor is running, It reads around 6.7v. If I try reading the positive side of the coil while using the engine as a ground, it read -1v...

The motor starts and runs fine though (as long as I short the solenoid).

Any ideas? I'm ready to take this thing to a shop, because I can't keep replacing solenoids...

[chautauquasun]

I also bought the Petronix ignition from Skidim but have yet to install it. Having read a few of these posts i am confused. Can I just install the Petronix in the distributor with the original coil and balast resistor or do I also need to up grade to a internally resisted coil?

thanks

[csuggs]

I used the original coil and ballast resistor. No problems.

[Blackntan90]

I also have had no issues with my stock ignition with pertronix ignitor/pickup installed for about 4 years now!