Will wrong ignition coil cause running issues?

[viper1216]

Hey everyone,

So here's a quick run down on the situation. Boat is an 88 Four Winns with an 88 Mercruiser 3.0. Bought the boat late last season. In my only time out with it, it ran fine for about 15 minutes and then died and wouldn't restart. Restarted at home on trailer without issue. Found bad head gasket and replaced that which included machining head. Replaced impeller and rebuilt carb as well. This season, getting it all buttoned up from repairs. It has a noticeable skip and stalls at idle. Temp gauge wasn't moving at all after running it for 10 minutes. Checked today and found stuck open t-stat. Replaced that and the fuel/water separator filter. After replacing these two items, engine will not start. Found it now has no spark (odd as it was fine yesterday) Pulled the cap (didn't look bad, but new one ordered and on the way). What I did find was that it has the electronic ignition conversion kit done. Serial on it is 05AD-V5, but can't figure out which kit was used. I tried attahcing a pic to the post, but it keeps giving an error. Did a little homework and found that the conversion kit needs to have a new coil used with it. (I think) Mine has the original coil, which is only putting out 8v, and I believe the upgrade needs 12v. So my question after all this, is it possible that having the wrong coil being used was the cause of the whole engine dying when I took it out? Maybe it was overworked and overheated and stopped firing? I've already ordered a Pertronix Ignitor II and a Flame Thrower II for it.

Thanks for any help!! This boat will be the death of me!!!!

 

[rmoreaux1]

Re: Will wrong ignition coil cause running issues?

Hey everyone,

So here's a quick run down on the situation. Boat is an 88 Four Winns with an 88 Mercruiser 3.0. Bought the boat late last season. In my only time out with it, it ran fine for about 15 minutes and then died and wouldn't restart. Restarted at home on trailer without issue. Found bad head gasket and replaced that which included machining head. Replaced impeller and rebuilt carb as well. This season, getting it all buttoned up from repairs. It has a noticeable skip and stalls at idle. Temp gauge wasn't moving at all after running it for 10 minutes. Checked today and found stuck open t-stat. Replaced that and the fuel/water separator filter. After replacing these two items, engine will not start. Found it now has no spark (odd as it was fine yesterday) Pulled the cap (didn't look bad, but new one ordered and on the way). What I did find was that it has the electronic ignition conversion kit done. Serial on it is 05AD-V5, but can't figure out which kit was used. I tried attahcing a pic to the post, but it keeps giving an error. Did a little homework and found that the conversion kit needs to have a new coil used with it. (I think) Mine has the original coil, which is only putting out 8v, and I believe the upgrade needs 12v. So my question after all this, is it possible that having the wrong coil being used was the cause of the whole engine dying when I took it out? Maybe it was overworked and overheated and stopped firing? I've already ordered a Pertronix Ignitor II and a Flame Thrower II for it.

Thanks for any help!! This boat will be the death of me!!!!

I bought my boat a 87 Renken 3.0 Alpha one in great shape and immediately ordered the Pertronix Ignitor II and the Flame Thrower II just like you stated you ordered. I hate messing with points and this system works great. You will like the new setup, however if your boat already had an electronic conversion done I would not have bought a new one simply a new coil. Make sure you are getting 12V to the coil as you may have a resistor you need to remove. The newer coils especially ones in the same branding have been chosen to work well with each other. Other coils will work as I used to only buy MSD Ignition components but strayed when they weren't readily available and had zero complications.

Your boat would run with a lower coil voltage but the spark wouldn't be as strong as it should. It really would not cause your boat to die after 15 minutes instead it might have caused your boat to misfire under a hard load but wouldn't have let it die.

My boat temp rarely goes up much on the gauge even when running it pretty good on the lake, I replaced my thermostat like you and expected mine to go up a little better but the water in the lake is cold and there is a bypass hole next to the thermostat so the water always flows even at start up. I want to install a restrictor in my bypass with a smaller hole to help temps raise a little. A colder engine has more power but a warmer one uses less fuel.

I would check for corroded or internally broken wires as this could cause it to work one minute and not the next. The noticeable skip and stall and idle could be carb related as the mercarb can be fussy. I had a lot of trouble with mine even after rebuilding it and still had a huge bog off idle and even took mine to my engine builder who has done a million carbs and he tore it open and said everything was rebuilt correctly. I took my mercarb off and bought a holley and it works great. The mercarb AKA rochester carb is usually a good carb but mine was acting nuts and I like the availability of Holley parts. I can tune it with no problems in every aspect of the power band quickly without any hassle. Once you get the new ignition put on check that it is getting proper voltage and it should fire right up. If not a bad or broken wire is probably the culprit.

 

[stonyloam]

Re: Will wrong ignition coil cause running issues?

Same ignition as mine. All you need to do is replace the purple resistance wire ( I just taped mine and rolled it up and tucked it out of the way) with stranded copper wire (#12 should do it) spliced into the purple wire going to the choke ( same wire the resistance wire is attached to). Solder connection is best, couple of coats of liquid tape to insulate the splice. Run that wire and the red petronix wire to the coil +. That will give you a full 12V to both your Ignitor II and Flamethrower II. Should be good to go. You might look into replacing the plug wires (might be the cause of the skip) while you are at it, I like the OEM Mercruiser set. It is hard to tell what your problem was, coils don't fail that often, might have been the electronic module.

 

[viper1216]

Re: Will wrong ignition coil cause running issues?

Thanks for the info gentleman. I know I probably could have held off on ordering a new ignition, but a lot of things on this boat have been hacked together, so I would rather just spend a few extra bucks and know I have a new solid performing system. This way I can eliminate it from the problem equation. I took the cap and rotor off today as I had gotten a new one just to test. They are ones from the auto part store for now, but I will replace them with the OEM merc stuff once I get the issues figured out. One thing I noticed was that the old rotor that was on there was definitely cut down and the one I bought is about an inch taller. Not sure why they would have cut the rotor down. Does anyone have the stock number for a rotor? I found a cap at West Marine, haven't found a rotor aside from the auto store.

 

[achris]

Re: Will wrong ignition coil cause running issues?

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