Re: 9.9 JOHNSON HELP!!!!
A Johnson 9.9 with electronic ignition (Magflash) would use a fairly large plug gap, so .042 sounds about right. I believe they also specified "end-gap" plugs which are not adjustable. The conventional "side electrode" plugs could be used if the motor was to be run at idle for long periods of time.<br /><br />If the propellor is a "through hub exhaust" type, the lower unit uses a slip clutch rather than shear pin. There is a place where a cotter pin retains the prop nut, is that what you're looking at? <br /><br />Look at the powerhead... there should be a recessed round freeze plug with some numbers stamped on it. Write those down, they may help someone here identify your outboard's model year.<br /><br />The 9.9 and 15 hp OMC motors have water intakes on both sides of the gearcase, below the anti-cavitation plate and above the propellor.
