92 115 Merc no spark to second cylinder down

[rickwatton1]

Hi: I have a 1992 Merc 115 hp 4 cylinder that does not have spark to the second cylinder down. What is the proper trouble shooting sequence.
Is the plug wire and cap replaceable? (My guess plug wire no cap yes)
Most likely the switch box but want to check cheaper solutions first! Thanks Rick

 

[Dave1027]

Re: 92 115 Merc no spark to second cylinder down

There is no distributor hence there is no cap.

You have three things you can swap to isolate, plug wire, plug or coil. There is one each per cylinder. Make sure there is not a bad connection from the trigger to the switchbox to the coil. If all that checks out you can test those components with a dva and voltmeter. It would probably be the switchbox.

 

[rickwatton1]

Re: 92 115 Merc no spark to second cylinder down

Dave the cap I am refering to slides over the plug. I have had non resistor caps fail on a snowmobile before and with reinserting into coil wire made a good conection. I did swap the number 3 and 4 wires to the coils and had spark on both. I may have misdiagnosed the no spark issue due to the bright sunlight. Going to check all plugs today it runs at just over 4000 rpm. May also be a weak coil.