1978 70hp johnson-power problems.intermitent

[bluebrownie]

Wondering if power pack problem...engine running sluggishly... put a new coil in this year and used powerpack last year... riding around with boat, sometimes runs low on power, did clear up and run ok....this year...now seems like losing power more often. Any ideas about what could cause this... didn't have spark on 1 coil/plugs ...replaced the coil and ended up with 2 coils not firing.. any ideas?????

 

[HighTrim]

Re: 1978 70hp johnson-power problems.intermitent

So you have determined that you are losing spark on 2 cylinders?

If swapping the coil from the bad cylinder with a known good one does not get you fire, you will need to look elsewhere. Start by ensuring that the coils ground is clean and shiny. Then look to the timer base. The timer base's resistance from the black/white wire to the white/black wires should be 10-20ohms. Next check the DVA output if you have the proper meter. You test the black/white wire to the white/black wires. You should get a reading of 0.5 Volts or more (while connected to the pack) to fire the pack. You will then need to test your power pack. You should read at least 150 Volts on the orange wire.