Can I Convert 73 Merc 7.5hp to Electronic Ignition?

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al_alamo

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Hi, I'm a first time poster to this forum but have spent many hours over the last week reading previous postings. I've seen many have upgraded to electronic ignition on larger outboards but no details on upgrading small motors. Could anyone who's BTDT share details of their experience. <br /><br />I just bought this Merc 75 but have been unable to get it started. The points were badly pitted so I cleaned them up but now the spark seems intermittent. Hopefully there's an electronic ignition kit to replace the old points and condenser. Thanks for any info you guys can provide.
 

Laddies

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Re: Can I Convert 73 Merc 7.5hp to Electronic Ignition?

why! if you don't want to replace worn out pts. you sure don't want to buy CD parts even used ones
 

phatmanmike

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Re: Can I Convert 73 Merc 7.5hp to Electronic Ignition?

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you sure don't want to buy CD parts even used ones
who said anything about CD?<br />west marine sells the kit for 65 bucks, but if you search online , i have seen the same kit for 35 bucks. no points, no fuss, just a running motor. nuff said
 

emckelvy

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Re: Can I Convert 73 Merc 7.5hp to Electronic Ignition?

I'm confused, a '73 Merc 7.5 Already has electronic ign. The points are just used as 'switching' signal to the cdi unit which should be part of the ign assy under the flywheel, if I recall how this year's ign was configured. What's your serial #??<br /><br />One good tip on these ign's is, very high voltage is seen at the points and the white insulator blocks where the points and external wiring mate up can develop cracks and leak off voltage to ground. This'll kill your spark. Before replacing any expensive ign components, replace these (2) blocks. Nothing wrong with that style of ign, and it's normal for the points to become pitted. Cleaning and gapping should suffice unless they're really bad.<br /><br />Let us know what the ser # is and we can pinpoint the year of your motor.<br /><br />HTH.........ed
 

al_alamo

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Re: Can I Convert 73 Merc 7.5hp to Electronic Ignition?

Thanks Phatmanmike for the West Marine lead--this is exactly what I had in mind. However, Ed now has me confused as I thought the presence of the points meant it was not electronic ignition. I don't see any reference to CDI or electronic ignition on the motor. The s/n is 3488538 which I've determined to be a '73 model. I haven't received my workshop manual so don't know if this year had a form of electronic ignition. My original thinking was: instead of buying 2 sets of points ($35+), I thought this would be a good time to convert to E.I. based on reported hotter spark, motor staying in tune since no gap to wear over time and eliminates the ongoing expense of points wearing out (assuming the E.I. modules are reliable--anyone with experience here?). Does anyone know conclusively whether this motor already has a form of E.I.??? This is a great forum and I appreciate everyone's contributions.
 

AMD Rules

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Re: Can I Convert 73 Merc 7.5hp to Electronic Ignition?

...Not for use wwith engines that have charging systems....
I found a few sources for the "Magnatune Ignition Systems" , but all of them have fine print in the description that says not to use them with an engine that has a charging system. My old 2cyl 40 Evinrude has a belt driven generator, through a voltage regulator. Will these electronic ignitions work, or not ?
 

WillyBWright

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Re: Can I Convert 73 Merc 7.5hp to Electronic Ignition?

Won't work on the Merc. Will work on the Evinrude.
 

Chinewalker

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Re: Can I Convert 73 Merc 7.5hp to Electronic Ignition?

Hi Al,<br /> Your motor has what's called a Low Tension electronic ignition. It has points under the flywheel with external coils. It is not uncommon for those motors to have very burned points and still work fine. BUT, the plastic housing that anchors the points can crack and allow the high voltage to leak out and weaken spark. Put a new set of points in there and you're likely good to go. It'll be well worth it, and cost less than the electronic Magna-tune dealies...<br />- Scott
 
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