Ignition ?'s '88 OMC 4.3

[Poager]

I have been doing a lot of research on here as I am trying to fix a problem with my dad's boat. It is an '88 Hurricane Deckboat with I believe a 4.3l V6 OMC. It has an MSD blaster 2 coil and a Thunderbolt IV ignition.

Problem we are having: boat usually starts without a problem. After 15 or so minutes on the lake the engine shuts off as if the ignition was turned off. 50% of the time it will start right up after the first time but will only last another 5 mins before shutting off again then usually will just crank but not start. We found that it is NOT GETTING SPARK when this happens. Sometimes before it completely shuts off we will be going a constant speed and it will cut out for a second but keep going, then eventually shut off. I have noticed the coil gets very hot... It usually starts right up by the time we get it home.

?'s I can't seem to find a straight answer to:

1. The tach is not working and have read this can cause ignition problems, is this true?

2. There are no diodes or resistors in line from the ESA to coil and it is hard to shift. Could this cause our problem and what is the proper resistance that should be here?

Answers to these questions and suggestions for things I should try are GREATLY appreciated. Tired of being towed back to the dock lol. Thanks Everyone!

 

[Icefire55]

Re: Ignition ?'s '88 OMC 4.3

the Tack is connected to the coil to see the # of spark per minute

if you are sure you don't have any spark (one plug removed, grounded on the block and try to start it) then it's something inline with it (coil, ignition), try to test each parts in the same range. unless you wanna try to change the coil and see if it's doing the same.

 

[lonemust]

Re: Ignition ?'s '88 OMC 4.3

I say CHANGE the coil it's dieing. I came to this by a simple thing you said "the gets hot", the coil should not get hot. When a coil works right(good) it cool to cool/warm but NOT hot. If a coil is hot to touch it means there is an interal short (a break down) in it. As it gets hot the windings inside are heating up the cooling oil inside, which is making the windings hotter causing them to expand and making the short open up more. This is when you lose spark, when it cools off the gap in the short closes back up giving you spark again. Eventually it will get to the point it won't start at all hot or cold. Another good way to tell if a coil is or isgoing bad is to look at it. If you see oil leaking out or you see the bottom bulging out, the coil will need replaced asap or risk being standed. And yes there is oil inside a coil so nobody tell me there isn't I've actually blown one up from overheating it. Did it just to see what would happen for fun. Yes I was hanging out with " uncle J.D." to much at the time.

 

[bruceb58]

Re: Ignition ?'s '88 OMC 4.3

I don't think the ESA will work with a thunderbolt ignition. You have to use the interrupt switches to ground the coil directly.

 

[Poager]

Re: Ignition ?'s '88 OMC 4.3

Thank you for the replies. If I replace the coil do i just pop it in there like the old one was or do i need to put resistors and diodes on it as other ppl have said? Could this have been the reason this coil got hot and failed?

Also Bruce, are you saying I shouldn't use the thunderbolt ignition at all or is there some modification to make it work with ESA?

 

[bruceb58]

Re: Ignition ?'s '88 OMC 4.3

You don't use the ESA. Instead of having the switch activate the ESA, you rewire the switch so that it grounds out the coil.

 

[Poager]

Re: Ignition ?'s '88 OMC 4.3

Ok, thanks Bruce. What is the disadvantage of wiring it that way? Why did they use the esa instead of just the switch?
Also, I replaced the coil (msd blaster 2). I will see if that fixes it, going to the lake on friday. The coil said it should be used with a .3ohm ballast resistor with points or stock distributer. Do I need this if I have a thunderbolt ignition? Could this be why my other coil failed and got hot?
Thanks again for the help!

 

[bruceb58]

Re: Ignition ?'s '88 OMC 4.3

OMC never came with a Thunderbolt ignition. It came with points. The ESA works fine with points.

 

[Poager]

Re: Ignition ?'s '88 OMC 4.3

Yes, so I will not need the resistor since it has aftermarket electronic ignition was my question.