Big twin flywheel compatibility

[dh_user]

Does anyone know if flywheel 580335 (1959 Evinrude 35hp) is compatible with flywheel 580334 (1961 evinrude 40hp)? Background and details below.

I'm restoring a 1961 evinrude 40hp (35524). The old flywheel (presumably it was original, pn 580334) had a bad taper, bad keyway, etc. (broken crankshaft looked like a big explosion). I found a flywheel from a 1959 35hp (I think pn 580335), and got it started after considerable effort, but it runs terrible.
. Confirmed fuel (bulb squeeze fills high speed circuit, and when running I can see the jet delivering fuel with the carb screen off at lower throttle)
. Compression is 105 top, 110 bottom (I honed cylinders, etc.)
. Confirmed decent spark across 1/4" gap using the basic gap tool
. Points gap is. 020 when the inspection port is right above the points (and cam is at high point for that cylinder)
. I don't have a timing tool for this engine, and the flywheel has absolutely no markings, but the points open and go to infinite ohms at two points I marked with a sharpie, pretty much exactly 180 degrees apart on the flywheel
I can't get this thing to run more than 45 to 60 seconds no matter what I do. Could it be the flywheel is that different? looks so similar.
Magnet size and shape looks just like the old one that came on the engine, but I'm just not sure.

 

[racerone]

But there are 2 timing marks on the flywheel that you can use to set the points.------The factory timing tool is nothing but an open " dummy flywheel "------You lock the magneto plate from turning.----Rotate flywheel to line up the timing marks.-----Remove flywheel and set points with your meter.-----Just takes a little longer then using the time saver fixture.