no spark from coil (omc 4.3)

[Skyhawk]

Put the boat in storage last year, ran fine when I winterized it. Just pulled it out last week and it wouldn't start. It was not getting spark from the coil.

I replaced the coil today and it still won't start. I pulled the coil wire from the cap to check spark, and it is not getting spark.

Any thoughts?

 

[Bondo]

Re: no spark from coil (omc 4.3)

Ayuh,... It's the Points that tell the coil When to fire,.. How are they,..?? Power,..?? Ground,..??

 

[bruceb58]

Re: no spark from coil (omc 4.3)

Always look to the points first and the coil last as far as replacing parts. First thing though is making sure you have voltage to the coil as there are so many things that could be preventing that from occuring.

 

[Skyhawk]

Re: no spark from coil (omc 4.3)

Thanx for reply guys.

The new coil was cheap so no worries, unfortunately I'm having a hard time figuring this out w/o using the "shotgun" approach and just throwing parts at it.

The cap, rotor, points, etc. "look good", I'll check the gap tomorrow but have no tool to check the condenser. If I have to I'll replace the former but I don't understand how it could run perfect, then sit for 5 months (winterized properly), then get no spark. Could worn points that were say, .010 too tight with little gap cause no spark?

My first thought was rodent damage but have yet to find any signs of such and have not seen any chewed wires but I'm still looking, there's a lot of ground to cover in an omc cobra, *sigh*

FWIW, the starter/solenoid was new 2 years ago, as well as the esa module, points/condenser, batteries and cables, the list goes on.

 

[jenningskb03]

Re: no spark from coil (omc 4.3)

maybe you could help me, I have a 4.3 alpha one with no spark, I already replaced ignition module, ignition module sensor in distributor, ignition switch, coil, and shift kill switch functioning, the green terminal on the distributor does not spark when I ground it out with the gap tester however the green/white wires that hook up to it do cause spark, Yes I have good connection from the batter 13.7 v and good 12 volts on the coil, and red wire

 

[Skyhawk]

Re: no spark from coil (omc 4.3)

Alright gents thread resurrection as I still have this problem.

I'm not getting any power to the new coil at all. Pulled off the coil lead at the distributor and checked it and there is no spark whatsoever from the coil.

Could this be the solenoid???? I suck at diagnosing electrical problems. It's the solenoid that "sends" the power to the coil correct?

 

[1ruralmailman]

Re: no spark from coil (omc 4.3)

not on my 4.3,there is a wire that goes from the battery positive side,and a power feed directly from the alternator. if you dont have 12 volts on the positive side she aint going to go.also it is not uncommon for points to corrode after storage to where they wont fire,all they need is to be polished with some emory paper.that being said you need to get power to the coil first,then see what happens.

good luck

 

[wire2]

Re: no spark from coil (omc 4.3)

....

I'm not getting any power to the new coil at all. Pulled off the coil lead at the distributor and checked it and there is no spark whatsoever from the coil.

Could this be the solenoid???? I suck at diagnosing electrical problems. It's the solenoid that "sends" the power to the coil correct?

With key on, power typically comes through a resistor wire to the coil + terminal. You should see ~4-9 volts to engine ground, (with points closed).

When cranking, the resistor wire is typically bypassed with a connection to the start solenoid to give a full 12 v to the coil for easier starting.

Remove dist. cap and crank. There should be a small arc at the points each time they open, indicating DC current. Or you can manually open the points with something insulated, there should be a spark from the coil HV lead to engine ground across a ?" gap each time.

As mentioned, polish the points surface with a fine abrasive if they've been sitting.

 

[Skyhawk]

Re: no spark from coil (omc 4.3)

The points have been cleaned and checked for gap, still nothing.

What do I need to check for juice at the coil? That's my problem, I can rebuild an engine from the crank up but when it comes to electrical, I'm in the dark. I'm assuming that is moot though as I pulled the coil wire from the dist. to check for spark and get nothing when she's cranked over.

Thanx for the help everybody.

 

[Eric 3.7LX Alpha 1]

Re: no spark from coil (omc 4.3)

A digital multimeter set to DC is the tool to help you, although you can use a test light, but it will not be as detailed in diagnostics. The light will show if you have power there, but not how much.

Here is a cheap one from Harbor Freight for $22.00
http://www.harborfreight.com/ac-dc-digital-multimeter-37772.html

 

[Bondo]

Re: no spark from coil (omc 4.3)

I suck at diagnosing electrical problems.
The points have been cleaned and checked for gap, still nothing.

Ayuh,... Did you read This,.... It explains Points Igntion...

 

[bruceb58]

Re: no spark from coil (omc 4.3)

You need to check the voltage at the coil with a meter ultimately.

Your man overboard tether is in place right?

 

[Don S]

Re: no spark from coil (omc 4.3)

The points have been cleaned and checked for gap, still nothing.

You don't "Clean" points, you replace them.

 

[Skyhawk]

Re: no spark from coil (omc 4.3)

You don't "Clean" points, you replace them.

Sure you can.

I just ran a piece of 1000grit between them a couple of times and checked gap, which is spot on, and like I said, they're new anyhow...

Anyway, I GOT HER RUNNIN' !!!!


There are 2 spring "tabs" that come off the point which moves and they attach where the coil lead and the condenser wire also attaches with one screw. Somehow the copper tab had worked it's way partially out and the screw was a hair loose. I removed the screw, lined everything up correctly, then put it back together and it fired right up. Now I just have to go slap the guy that replaced the points last year, lol. In the future I'll be replacing them myself to make sure it's done correctly.

Thanks to all that replied!!

 

[bruceb58]

Re: no spark from coil (omc 4.3)

By running the grit over them you ruined them so get some new points. Also, set them with a dwell meter and check your timing after.

You would have found your problem a long time ago if you had hooked up a dwell meter and checked the dwell while cranking.

 

[victoryinerie]

Re: no spark from coil (omc 4.3)

maybe you could help me, I have a 4.3 alpha one with no spark, I already replaced ignition module, ignition module sensor in distributor, ignition switch, coil, and shift kill switch functioning, the green terminal on the distributor does not spark when I ground it out with the gap tester however the green/white wires that hook up to it do cause spark, Yes I have good connection from the batter 13.7 v and good 12 volts on the coil, and red wire

I had a similar issue not sure if it will help, but it was the rotor, had a hard time taking the old one off and there was an small piece of plastic still it grove of the shaft which was causing the rotor not to seat all the way down. Not sure if it will help but it is worth a try.

 

[Skyhawk]

Re: no spark from coil (omc 4.3)

By running the grit over them you ruined them so get some new points. Also, set them with a dwell meter and check your timing after.

You would have found your problem a long time ago if you had hooked up a dwell meter and checked the dwell while cranking.

*sigh*

How so? Is there an anti corrosive coating on there I possibly rubbed off? I only swiped the grit through there twice and looking at it now, I realize it was in fact 1500 grit so not much more abrasive than a piece of paper, lol. I'm growing tired of points ignition and wish there was an electronic conversion for these omc's with the shift interrupt.

 

[LAC_STS]

Re: no spark from coil (omc 4.3)

*sigh*

How so? Is there an anti corrosive coating on there I possibly rubbed off? I only swiped the grit through there twice and looking at it now, I realize it was in fact 1500 grit so not much more abrasive than a piece of paper, lol. I'm growing tired of points ignition and wish there was an electronic conversion for these omc's with the shift interrupt.

THERE IS!

There are a couple different options.

You can buy an elec dist and a newer style ESA module which is elec IGN compatible.

You can buy an elec dist and wire the shift assist via the resistor from Radio Shack method (search this forum)

You can buy a Delco dist and wire the shift assist like a merc. There is a thread a little while ago thats titled somethinglike "electronic IGN Delco distributor on OMC 5.7"

I posted the instructions that a marina gave me on how to wire up a Delco dist.


Just do some searching.

 

[Davekellogg]

I’ve a 4.3 OMC Cobra, won’t start, tgere is only 4.9 volts to the positive side of the coil, is this the ignition switch?

 

[Bondo]

8 year old thread,..... closed,....

Dave,.... start a new thread of yer own, in the OMC forum,....