115 Johnson timing

JvZ

Recruit
Joined
Feb 28, 2005
Messages
3
Hi. Can somebody please help me with how to check and adjust the timing on the 115 Johnson (1981).<br /><br />Which plug, looking from the back of the motor is the number 1 plug(the top one on the right hand side)?<br /><br />Thanks
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: 115 Johnson timing

Cyls numbered as follows.<br /><br />2.....1<br /><br />4.....3<br /><br />(Timing At Cranking Speed 4°)<br />(J. Reeves)<br />The full spark advance can be adjusted without have the engine running at near full throttle as follows. <br /><br />To set the timing on that engine, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary). <br /><br />Rig a spark tester and have the gap set to 7/16". Hook up the timing light to the #1 plug wire. Crank the engine over and set the spark advance to 4° less than what the engine calls for. <br /><br />I don't know the full spark advance setting your engine calls for, but to pick a figure, say your engine calls for 28°, set the timing at 24°. The reasoning for the 4° difference is that when the engine is actually running, due to the nature of the solid state ignition componets, the engine gains the extra 4°. <br /><br />If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4° which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place. <br /><br />No need to be concerned about the idle timing as that will take care of itself. The main concern is the full advance setting. <br /><br />Be sure to use your own engines spark advance settings, not the one I picked out of the air here in my notes.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: 115 Johnson timing

I'm in slow mode today! <br /><br />Sorry Joe, I was typing at the same time.
 

reeldutch

Lieutenant
Joined
Feb 2, 2004
Messages
1,340
Re: 115 Johnson timing

why dont you have to set it under load with a testwheel?<br /><br />just a question would like to know stuff<br /><br />thanks reeldutch
 
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