2 Timing Notches on Crankshaft Pulley

Wed Sep 25, 2013 8:36 am

There are two notches on my '50 Cub's crank (fan) pulley, about 3/4" apart, or about 17 - 18 degrees. What are two notches for?

The magneto trips (clicks) at the second notch - is that correct?

The operator's manual warns that the magneto may need to be retimed if the engine is cranked while the distributor body is off. Unless I missed something, Is there a way to get the points "breaker arm rubbing post" onto a high part of the distributor cam without rotating the engine?

Re: 2 Timing Notches on Crankshaft Pulley

Wed Sep 25, 2013 9:04 am

yes that is correct. Apparently your pulley has been changed at some time, the 2 notch pulleys were originally on tractors with distributors. The first notch is 16 degree advance for using a timing light to set time of distributor. Most likely someone broke the original trying to remove it with the wrong puller.

Re: 2 Timing Notches on Crankshaft Pulley

Wed Sep 25, 2013 10:22 am

OK, If the mag trips on the second mark, am I OK? Or should I use a timing light and use the first mark?

Re: 2 Timing Notches on Crankshaft Pulley

Wed Sep 25, 2013 10:32 am

Yes it should be static timed at the second mark

Re: 2 Timing Notches on Crankshaft Pulley

Wed Sep 25, 2013 12:32 pm

Sounds like I'm OK - thanks all.