Sounds like a 7hp JAP industrial engine engine I had, hand crank start
and normally went on the 2nd go but if you left it standing for a year
then it required the points cleaning or it wouldn't start. After
cleaning the points then starting was again 2nd go.

David Anderson wrote:

I own a vintage International Harvester single-cylinder hopper cooled farm
engine in mechanically excellent condition. I believe the model designation
is LB, and probably dates from the late 1920's or 30's. It used to start
on the first crank, but no more. I suspect the magneto is weak. Any
suggestions how to bench-test this mag? I have a professional quality
digital VOM but no specialized magneto tools. The mag has a centrifugal
device that "snaps" at slow speeds. Regards, Dave Anderson