6v flywheel on 1500. What do I need?

Stick the flywheel on and hand tighten. Check endplay to see if shims need to be changed.

When you get the shims correct, replace the oil seal. Press it all the way in to the stop. Lube the seal and the shims.

Put a 4-hole metal gasket between crank and flywheel to seal. (Or the paper one in a pinch.) The gasket will increase the endplay by a hair.

Tighten gland nut to 250 FOOT Lbs !

You won't do this with a plain 1/2" breaker bar. Needs a 3/4" (solid) bar plus a 4 foot long cheater pipe. And it's really tough to hold the flywheel with the usual flywheel lock, expecially working alone. Better is to get a 4/6 foot long steel angle (or similar) and bolt it to the flywheel perimeter.

May be a dumb question but.... isn't the 40 hp crankshaft a stepped crankshaft?

I am not sure if I remember right, but a stepped flywheel will not fit on a non-stepped crank. Correct?

non-stepped crank.

Not dumb at all.

You're right about the configuration, but the 40HP (6V) flywheel will fit the 1500/1600 crank. The 1500/1600 (12V) flywheel doesn't work on the 40HP crank.

And for those keeping score , yes, there were some rare exceptions and, yes, the 1300 engine was a transition with both types of crank used.

Karl, I wish I could find a dimension drawing to back up my (failing) memory. I'll keep looking.

Jim