Johnson HD-25 running issues

[aquasonic]

quote Buccaneer:

…yesterday I put at dial indicator in the plug holes
and hooked up a buzz box across the points to get
the two cylinders synced in their firing as close as I could…

Hey Bucaneer, how did you do this? I have the timing fixture made by Frank Robb, and use it along with a multimeter for 1950’s OMC motors with universal ignition. I had always wondered if somehow it could be adapted to the older TD/HD type of ignition, but without the timing marks on the magplate, wasn’t sure if timing adjustments are possible.

Improvise-Adapt-Overcome

[Buccaneer]

Aqua, I used a small engine TDC gauge that has the 14 mm
thread for the plug hole.
Pre-set the points at .020, then placed
my buzz box across the points for the cylinder on TDC.
Moved the mag plate until the points just start to open,
and the buzzer pitch changes.
I marked the mag plate lever position in case it gets bumped,
but make sure it doesn’t move is best.
I then set-up for the other cylinder for TDC
and re-hookup my buzzer.
I adjust the points so they just open, and the buzzer
goes off, with the mag plate in the same position as
the other cylinder.
Before I re-set the points using the buzz box, I’d have to move
the mag plate about 1/2" travel between the two points
where the box box went off for each cylinder.
Not sure if any of this makes sense, or if I even know what
I’m doing, but hey, it worked for me!

Prepare to be boarded!

[aquasonic]

That’s an intriguing method. I haven’t used a TDC gauge before. Does it look for the minimum overhead piston clearance to determine TDC? I think I’m starting to get the idea. I’m thinking that without the factory timing mark, and a timing fixture, the pistons may not fire exactly 180 degrees apart, but not sure how important that is. I’d really like to hear Franks thoughts on this. Thanks Buc.

Improvise-Adapt-Overcome

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