Do cracked "magnets" matter on merc V6 150 Ignition coils?

[pjbrownva]

Hi,

For part number 339-832757A4, the coils have black -carbon like material around (they might be magnets, I'm not sure)...

Does it matter if the black part is cracked?

What does that part do, and what's the impact if they are cracked.

Thanks, Scream N Fly.

-Philip

[HStream1]

Yes it does. It can cause the coil to act sporadic in the firing sequence and its not going to fix itself its only going to get worse.

[VooDooChild 1267]

For me it meant a wasted nice sunny day.My motor ran ok on the muffs,but when it came time to get up and go it was a stumbling mess.I ended up having 2 that were cracked.Even with the cracks they were puttin out spark,just very weak.

[bullet123]

Are you talking about the coil itself is cracked or the plastic coil holder?

[Merc 2.5]

His coil are blue so it have to be the plastic shield he's talking about. I would think

[Merc 2.5]

Then again he also going after a weak spark issue I believe

[pjbrownva]

Then again he also going after a weak spark issue I believe

Yes, I am chasing down a weak spark on a single cylinder at high speed.

I actually have black coils (it's a motor that I rebuilt from spare parts... block, carbs and all "hardware" are from an '88 or '89 2.0L 150. Flywheel & all electrics are from a '93 ).

The part that I'm referring to is the black part in this photo with the tape on it.


When you take the rubber case off of the ignition coil, you can see it.


I'm pretty sure that HStream1 gave me the right answer... what I'm seeing is no spark at higher RPMS (I've called it a weak spark, but that may technically be incorrect).

Yes it does. It can cause the coil to act sporadic in the firing sequence and its not going to fix itself its only going to get worse.

Anyway, at least a few of my ignition coils have one or more cracks in this black part located inside the rubber and around the plastic.

I just ordered 6 new made-in-china coils from ebay...



Hopefully they will actually work.

If they are made to the proper size, then maybe I'll just replace the part this is cracked on my existing coils, with the new, not-cracked portion from the inexpensive coils I just ordered.

(Although I already have buyers remorse, as I wish that I had ponied up $31 each, or $186 total to get the CDI brand coils from ebay... $56 more
for known good quality should have been a non-brainer... oh well)

I also picked up a used stator with trigger for $140 off a "make an offer" on ebay,


and got some inexpensive but new wires off of a website

and I have a new flywheel and trigger coming from bullet123 (new to me, that is).


With these parts swaps, plus the new (inexpensive) switch boxes I bought last year, I should be up and running.
(And I saved the original parts as well, so I can swap the originals back to check if necessary).

My wife gave me the thumbs down on buying a 2.4 drop on head listed for sale here, and she's also complained about the time I've spent trouble shooting the motor (I bought a DVA adapter, but haven't used it yet.)....

So..... when she wasn't looking, I snuck into her purse, stole my balls back, put 'em on, and told her I was spending a few hundred on new and used parts to replace everything that is likely bad. (Then I put my balls back in her purse, before she noticed and got mad!)

Anyway, it sounds like the cracked parts around my coils are possibly the real culprit, since I know they are cracked, and I'm experiencing the symptoms that HStream1 mentioned, but with all of these new or different parts, I should be able to be up and running in no time!

I'm lookin' forward to that... it's about #$@# time!

I plan to save my funds, and maybe down the road pick up a used optimax, a used 4 stroke, or maybe just a fully-dressed drop-on optimax head and new cowl with bottom plate.

When my wife sees my new bank statement, I'll probably have a true scream and fly...

She's likely to scream, at which point I'll fly to the boat for some relaxation. (hehe!)

Cheers!


BTW,
If anyone *knows* that the parts I bought are utter crap and not worth even trying, then by all means chime in and save me some grief.
But barring known problems, I'm gonna give these parts a try... since I don't really have many fund$ to spend on the boat right now...

That is, unless I'm willing to move out of the house and plan to live on the boat for a while (if you know what I mean). :-)

LOL. It's all good, though. Plus, I've been spending wrench time on a few of my other mechanical toys, like modding my 4runner, improving an old jag convertible I've had for more than a decade, and even fixing the A/C and few other issues on my wife's '89 420SEL Benz... which is her daily (and only) driver... and it was hard for her to complain about me spending time working on HER car. ;-)

-Phil

[pjbrownva]

For me it meant a wasted nice sunny day.My motor ran ok on the muffs,but when it came time to get up and go it was a stumbling mess.I ended up having 2 that were cracked.Even with the cracks they were puttin out spark,just very weak.

I think that's my root cause. The sparks all look good at the dock at low RPMS. At higher RPMS, one of the coils loses its spark all together, and when I run under load, I have no power, struggle to get up on plane (that is, when I can get on plane), and the top speed is much-much lower than it should be.

I'm lookin' forward to getting all of these new (or at least new to me) parts. I think I'll put them all on, except for the coils, I'll try keeping my OEM merc coils, and just replace the cracked part around the coils with the new, not-cracked pieces from the cheap replacements.

Can running the coils with that part cracked damage the coil? I ask, because if the answer is yes, then maybe I should just swap in whole new coils.

[bullet123]

I have dozens and dozens of coils. If the Chinese crap don’t work, shoot me a pm and I will send you some coils for cost of shipping.