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Help with Mercury 2.2hp Outboard

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funWithEngines

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Hi Folks. I'm trying to repair an older Mercury 2.2hp Outboard. The engine is ~early 80s vintage with S/N A819553.

Problem is in the ignition system - no spark. We've debugged the following:

- Kill switch is disconnected, and not grounding the coil; Replaced the condensor.
- Exciter coil measures ~1.3 ohm. Ignition coil primary measures ~1.5 ohm to ground, secondary measures ~5K ohm to ground. These all seem fine to me.
- Output from exciter coil, condensor, and breaker point circuit (under the flywheel) measures ~21v peak when pull starting
- Output from ignition coil is enough to make you (me!) jump when pull starting , but not enough to spark across the plug.


So my question is what to try next?

- Is the exciter coil not putting out enough punch to drive the ignition coil?
- Is the ignition coil not strong enough to step up the voltage to drive a spark?
- Is there something else we should be considering?

Thanks in advance for your help...

-kl
 
You are getting 5K resistance on the secondaries?

My book give an acceptable range of 425-575 ohms for the secondary.

Unless you mis-stated your result, the coil could be your issue...
 
Hi galamb,

Thanks for the tip. We measured several times - each time we got the same result.

Just to be certain - the secondary is measured from the plug wire to ground, correct? Likewise the primary is measured from coil input (low voltage side) to ground?

Also - does your book provide any range on the resistance of the exciter coil or the primary?

Thanks!

-kl
 
I have -

Exciter coil (with breaker points open) - red lead to the black/white wire, black lead to engine ground (1.5 ohms)

Primary - red lead to low voltage side, black to engine ground (.81-1.09 ohms)

Secondary - red lead to spark plug wire, black to engine ground (425-575 ohms)
 
Thanks galamb. One other thing I would like to check before ordering a new ignition coil. We made a quick measurement of the dwel for the contact points. It measures 320 degrees, which sounds large to me. Do you know the spec so we can adjust and confirm?

Thanks
 
40 degrees (off dwell) does sound alot, I would expect something more in the 25 range.

However, I have zero specs on the Phelon system (none published in my manual) and the points on this model operate (backwards) to Merc's "phasemaker" thunderbolt ignition.

You might try a websearch for "phelon ignition" and see if there are any specs out there.

Sorry, that's all I got...
 
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