How to Set the Points on Johnson Outboardsby Chris Stevenson
The ignition points in a Johnson outboard motor function like any other ignition points, in that they transfer a magneto spark through two point contacts. The point contacts open and close according to the camshaft rotation, which opens and closes the valves. The points send voltage to the spark plug wire and onto the spark plug. Ignition points can suffer from wear, carbon soot and burning. When the point contacts wear or accumulate carbon buildup, the dwell (ignition timing) changes, resulting in a poorly running engine.
Place the motor, if trailered, in an accessible spot. Remove the key from the ignition, if so equipped, and activate the main ignition cutoff switch. Trim the motor level, if you have electric trim. Place the motor in the full down position by removing the motor tilt pin and adjusting the motor for the full down position. Replace the tilt pin. Unclasp the top engine cowl snaps and pull the case off. Use a socket to remove the case, if it uses bolts for fasteners.
Place a flywheel strap around the perimeter of the flywheel and hold it taut. Use a socket and long-handled ratchet to loosen and remove the flywheel nut. Have an assistant to help you with this operation if you need more leverage. Place the three holding hooks of a harmonic balancer puller underneath the bottom lip of the flywheel. Screw the threaded pulley bolt onto the depression in the crankshaft end. Turn the pulley bolt clockwise with a socket and wrench, breaking the flywheel loose from the shaft.
Pull the flywheel off. Use a screwdriver to remove the ignition points case screws. Set the case aside. Examine the ignition points, which might be a single set or a dual set. Each point unit has a lever arm, rubbing block, contacts and two screws each. If replacing the points, wedge the small spring retainer open that hold the condenser wire to the points -- two wires for two condensers. Pull the wires free.
Use a flat-head screwdriver to loosen and remove the two screws for one set of points. Remove the other two screws from the other set of points. Pull both sets of points out and discard them. Place the new points in their mounting grooves. Screw all four mounting screws in by hand, then tighten them with a screwdriver, just enough so they fit snug.
Place a flat-head screwdriver in the adjusting slot that opens and closes the points. Adjust the points so that the small amber-colored rubbing block on the points arm contacts the lobed shaft. Turn the flywheel shaft until the rubbing block rides up and sits upon the highest part of the shaft, which will be the lobe. Place a feeler gauge, set at .20 inch, between the two point contacts and adjust the contacts to close over the feeler gauge. Refer to your engine manual for the precise inch gap.
Pull the feeler gauge up and down, making sure you have a slight drag on the gauge. Tighten both screws. Perform the identical adjusting procedure on the other set of points. Place both condenser wires back under their spring clips on both sets of points. Apply a finger dab of marine grease on both shafts. Replace the points cover and screw it down with a screwdriver.
Dab grease on the crankshaft and threads. Place the flywheel over the shaft and push it down. Put the nut back on the shaft and turn it clockwise by hand. Wrap the flywheel strap around the flywheel. Tighten the flywheel nut with a long-handled ratchet and socket. Place the engine cowl case back on the top of the engine and clasp the hold-down snaps. Replace and tighten the cowl case bolts with a socket, if you have removed these types of fasteners.
Things You'll Need
- Engine owner's manual
- Flywheel strap wrench
- Assistant (optional)
- Harmonic balancer puller
- New points (optional)
- Feeler gauge
- Marine grease
Chris Stevenson has been writing since 1988. His automotive vocation has spanned more than 35 years and he authored the auto repair manual "Auto Repair Shams and Scams" in 1990. Stevenson holds a P.D.S Toyota certificate, ASE brake certification, Clean Air Act certification and a California smog license.