Magneto forgets the setting

[cjsanchez]

Hello there, does anyone know why after a few days of not riding the mule I have to go back and wiggle the magneto up and down, what until I hear some pops and blue/black smoke for it to settle back on a perfect idle and rev up.
Then the mule runs pefect, if I ride it again a day later it runs great. If I let it sit for more than a day I'm back with the stutters when i rev it up and it has low power...
Then to fix the problem I just loosen the mag and find a good "place" for it to start with the perfect idle...

Please help

[Chuck W.]

My initial thought is that the nut holding the drive gear is loose, or a problem with the impulse unit. Either way, it needs to come off and be inspected

[Grummanflyer]

Yup, as Chuck said, could be sheared key on the impulse coupling or could also be broken spring in the coupling. My Super Cub was doing that same thing and it was a broken spring.

GF

[muleman7]

By manually turning the Mag gear you can check that the coupler spring is working. When you turn the gear it will spin easily until the pawl hits the stop pin then it will resist turning as the coupler spring tightens an when the outer coupler contacts the pawl it will release from the stop pin and turn rapidly with a resulting SNAP or CLICK.

The following pics will help you inspect the Impulse Coupler and check the Key.

Removing the Coupler



Coupler Removed



Coupler Top View



Coupler Bottom View check that the spring is present and working on the pawl. The 15 represents the Lag Angle or retard when cranking the engine manually. Using an electric starter generally spins the engine fast enough to pull the pawl in so the coupler does not engage.



Coupler Removing Tool I had to modify the ends to fit into and under the Coupler

[cjsanchez]

I'm still trying to find time to open up the mag and check out stuff.
I'll let you know how it goes, thanks all for the awesome help you guys give!

CJ