1976 25hp johnson points and timing

[jessegriep]

hi, i have a 1976 25 hp johnson. i took the fly wheel off because it was hitting the magneto and now that i did that, the motor runs rough at half throttle? it runs great at idle and wide open. there is only one magneto on this engine and i was wondering how do i set the timing on it so it runs good? i watched videos on how to set a two magneto engine, but not just one?

 

[Joe Reeves]

Re: 1976 25hp johnson points and timing

I have no idea what you're speaking of ie.... one magneto, two magneto...... align the coils and set the points as follows. The timing is set by the key aligning the flywheel with the crankshaft. If the key isn't sheared, the engine is in time.

(Magneto & Driver Coil Alignment)
(J. Reeves)

To align the coils properly, have the metal vertical portion of the coil yokes aligned with the inside edge of the bevel that exists on the top portion of the aluminum seat upon which the coils sit. This creates the proper distance between the coils and the flywheel magnets. Faulty alignment creates friction and the yokes of the coils heat up, turn blue and expand.

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(Point Setting Of Magneto Models)
(J. Reeves)

Set the points as follows. Have the flywheel key aligned with the fiber rubbing portion of the ignition points. Adjust the gap so that a .020 gauge will pass thru but a .022 will not. Should there be any question of the points being dirty (touching the contact with your finger would cause them to be dirty), clean them with a small brush and acetone or lacquer thinner.

NOTE 1: Should the operating cam have a small portion on it with the word "SET" imprinted, align this portion with the fiber rubbing portion instead of the flywheel key.

NOTE 2: Should the cam have the word TOP embossed on the top of it, that is a cam that could be installed upside down and this is simply telling you which side is up. It is not a position where one would set the points.