1972 Evinrude Lark 50 hp start problem

[dartagnan111]

Can't seem to start engine. At first it seemed to try to start, but was barely turning and it was intermittent. Now it is still intermittent, but starter does turn, just doesn't engage the engine. By intermittent I mean it often does nothing at all. Upon reading some other threads, found out the starter raises up the shaft from the force of the spin to engage the engine, but has to turn fast enough for this. Also checked out a few troubleshooting steps from other forums:

-Turning the top of the starter does allow it to move up the shaft freely, so is definitely not stuck
-Ran jumper cable direct from battery to starter, starts it spinning immediately, but does not engage engine, and shuts off after about 10 seconds.

Did not test anything else thus far, such as the solenoid, but it seems like the starter itself is having issues? Any thoughts from anyone? Also, if the starter is the problem, I did find starters for about 50-60 dollars, but how do I know if they are compatible for my motor?

 

[joereeves]

The engine must crank over at least 300 rpm in order for the stator under the flywheel to provide the proper AC voltage to the powerpack capacitor. A slow cranking engine will have weak, erratic, or no ignition.

Always check the spark with the spark plugs out so to provide the fastest possible rpm.

To test the starter..... Run good known battery cables from a known good fully charged battery directly to the electric starter. If the electric starter still emits a problem, correct that before going any further.

 

[dartagnan111]

The engine must crank over at least 300 rpm in order for the stator under the flywheel to provide the proper AC voltage to the powerpack capacitor. A slow cranking engine will have weak, erratic, or no ignition.

Always check the spark with the spark plugs out so to provide the fastest possible rpm.

To test the starter..... Run good known battery cables from a known good fully charged battery directly to the electric starter. If the electric starter still emits a problem, correct that before going any further.

Thanks!