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1994 48hp johnson ignition or power pack

T

thedude

New member
I got a 48 hp johnson that was passed down to me from a relative. It sat for a while (~4 years) w/o being run. I had the carbs rebuilt and the water pump replaced. Both cylingers had good compression (150). Last weekend I put it in the water to see how it would run. Started and idled fine. I throttled up after cruising out of the canal and it ran great until I throttled down. Then, it started sputtering. It finally quit when I ran it at idle for a bit. Tried again the next day with the same results. Got to looking and the bottom cylinder wasn't firing. You could tell it would fire every now and again when I throttled up. I put a new ignition coil on it yesterday and ran it on the hose. Same results...at first. I pulled the lead coming from the power pack that goes to the coil and cleaned it out a bit. It wasn't really that dirty in the first place, but I figured, why not? Put it back on the started the motor and it ran fine. Getting spark on both cylinders. I ran it on the hose for 20-25 mins. I put it in the water today pulled away from the dock and put the hammer down. It ran great for about 1/4 mile, then, same story. The bottom cylinder wasn't firing. Idled back to the ramp. Does this sound like a cut and dry power pack problem? Is there something else I should be thinking about? Will a bad power pack burn up a good ignition coil? I also put new plugs in both cylinders. Thanks in advance for any advice.
 
The fact that you cleaned the coil lead and the result was an improvement is a clue. Make sure that the inner wire of the spark plug wire is actually touching the spring coil terminal inside of the spark plug boot..... and check all other connections pertaining to the ignition.

(Magneto Capacitance Discharge Coils - Continuity Test))
(J. Reeves)

Check the continuity of the ignition coils. Remove the primary orange wire from whatever it's connected to. It may be connected to a powerpack screw type terminal, a rubber plug connector, or it may simply plug onto a small boss terminal of the coil itself.

Connect the black lead of a ohm meter to the spark plug boot terminal, then with the red ohm meter lead, touch the ground of the coil or the powerhead itself if the coil is still installed.

Then touch (still with the red lead) the orange wire if it's attached to the coil, or if it's not attached, touch the primary stud of the coil. You should get a reading on both touches (contacts). If not, check the spring terminal inside the rubber boots of the spark plug wire. Poor or no continuity of a coil is one reason for s/plug fouling.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay store at:

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store
 
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