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Mercury / Tohatsu 5hp outboard no spark

pilotmarcus

New member
All,
I have a 2005 ME5M 4ST Mercury (5HP) - I think it is now Tohatsu engine.
Got it from a friend and after changing the carburetor and spark plug it was running again.
Unfortunately somehow the bow line got caught in the prop. Result is no more spark on the spark plug.
I checked the kill switch and also the resistance on the ignition coil (primary 0.3 Ohm, secondary 11.6k Ohm), I could not find any specs if these indicate that the coil is ok.
Also is there anything else that could be broken by the sudden stop of the engine, preventing it from firing?

thanks,
Marcus
 
Depends whether you have the single-piece ignitor or separate CD and ignition coil. Probably the latter. None of this should be affected by the sudden stop from wrapping a line around the prop. The Factory service manual has specs for the CD and exciter. If anything grounds the brown wire to the kill switch, that will kill the spark.
 
Thanks very much for the reply, I looked at the specs for the engine/coil and it gives me no resistance measurements, only the Volts. That is a bit difficult with just a multimeter and cranking at the same time. Any other idea what could have caused the spark not firing by a sudden stop of the engine.

Regards,
Marcus


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You need either a meter with DVA, or a DVA adapter. You must use an analog meter, not digital... and the ohm battery must be 3v or less, lest you burn out the CD. There are also resistance measurements in the Tohatsu Factory service manual.
 
I managed to get a DVA adapter and it even works with an analog Multimeter.
It seems that all voltages are there, so the ignition coils is most likely to be faulty.
I did a quick search on spare parts and could only find a company in Singapore selling the ignition coils and they state that it is for 2 stroke engines.
Any tip where I can order the coil?

thanks,
Marcus
 
Analog is best on outboards.
Any Tohatsu dealer, even I, can sell you
3H6060500MIGNITION COIL$43.88
 
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