Engine problems again

[Rinker85]

Hello,

I have a 1984 2.5 L OMC. Today on the lake I had problems with power and backfiring after the boat ran great for 2 hours.

Last weekend I thought it was water in the fuel. I changed the fuel water separator and the fuel pump filter. The plugs are brand new. New fuel pump last fall. New ignition conversion kit last summer. The timing is perfect.

The problem that I am having is after the boat runs for about two hours it looses power real fast, backfired once today and completely stalled out.

I'm really at a loss for what is going on. Why does it run great for 2 hours then acts up. It did this today, last weekend and I remember it happening late last fall.

Thank you

 

[alldodge]

New ignition conversion kit last summer.
Why does it run great for 2 hours then acts up.

Hard to say but would think its heating up and the ignition is failing. Which ignition did you install?

 

[Scott Danforth]

Reinstall points and check. Sounds like the ignition conversion AD mentioned

 

[Rinker85]

Hard to say but would think its heating up and the ignition is failing. Which ignition did you install?

I installed Hot Spark ignition

 

[Maclin]

Could be a mis-match or improper wiring for internal vs. external ballasted ignition coil. Check the instructions again, double-triple check the wiring, be sure what type of coil is on there and if the ignition circuit provides ballast or not.

Here is an odd one from my past...
Brother had just bought a late 50's classic car and those were its's symptoms. Drive around for an hour or two and it would start backfiring and stall, then very hard to start until it cooled down. I was not there during the debug session, but the positive and negative wires to the coil were backwards. Was hard for me to believe it even ran, but there it was. Well, second hand report anyway, but brother is ok on points ignitions. That one may have been a dual point as it was a 392 Hemi, memory fails.

 

[alldodge]

Looks like the HS does require a resistor going to the module and needs at least 3 ohm internal resistance to the coil. Some have had issues. With it backfiring this is either the ignition or the motor timing.

Have you run through the troubleshooting guide?

http://www.hot-spark.com/Troubleshooting.pdf

 

[Rinker85]

Looks like the HS does require a resistor going to the module and needs at least 3 ohm internal resistance to the coil. Some have had issues. With it backfiring this is either the ignition or the motor timing.

Have you run through the troubleshooting guide?

http://www.hot-spark.com/Troubleshooting.pdf

I just printed the 6 page troubleshooting guide for Hot Spark. Waiting for it to stop raining so I can take a look at it. When I installed it last summer I did update the coil to the recommend resistance, but I did not install a ballast resistor.

From Hot spark troubleshooting : "Voltage must never exceed 13.7 volts at any RPM level. Too much voltage can cause the ignition module to overheat and run erratically or fail. "

I remember seeing 14 volts on the voltmeter yesterday. Dose a bigger coil cause that much voltage? I believe I installed a Duralast LU-800

 

[alldodge]

Voltage must never exceed 13.7 volts at any RPM level

To me this is an issue, because the alternator puts out 14 to 14.5V

 

[Rinker85]

To me this is an issue, because the alternator puts out 14 to 14.5V

So are you saying it’s not good to install a resistor or too many electronics to go bad?

 

[alldodge]

So are you saying it’s not good to install a resistor or too many electronics to go bad?

All I'm saying is if there statement is true its a wonder any of them work. It also says:

Ballast Resistor: If the coil's primary resistance is not quite enough or is borderline, you can wire an external ceramic
ballast resistor (with 1.0 to 1.5 Ohms resistance) between the coil's + terminal and the red HotSpark ignition wire:

So tells me that it should have a resistance wire or ballast resistor installed to drop the voltage to the coil and reduce the amps no matter which coil. Take this comment with a grain of salt because this is the first I've heard of HS on anything including a boat. Don't even know if its USCG certified

Also says something about a capacitor might be needed if connected to a tachometer

 

[Rinker85]

All I'm saying is if there statement is true its a wonder any of them work. It also says:



So tells me that it should have a resistance wire or ballast resistor installed to drop the voltage to the coil and reduce the amps no matter which coil. Take this comment with a grain of salt because this is the first I've heard of HS on anything including a boat. Don't even know if its USCG certified

Also says something about a capacitor might be needed if connected to a tachometer

I here what your saying and appreciate your advice. The truth is I'm kind of fed up with the electronic ignition and ready to go back to points. I do have to say though ever since I installed it, the boat runs great. Well at least for the first couple of hours. LOL. When I have posted in the past about the boat running better with the conversion kit people on this forum have stated that if the boat runs better then I never had the points adjusted right in the 1st place. I disagree. I used a feeler gauge and dwell meter every time. And have checked timing after as well.

What about Pertronix ignition kits?

 

[alldodge]

Have heard the Pet being used by most, there have still been problems but nothing about burning things up after install. If you have the funds I would go with Delco EST, otherwise suggest stick with points