Starter Keeps Spinnin Me Round Right Baby Right Round

[2jmotorsports]

83 SC, stock starter motor (probably original one).

Ive been having some interesting starter behavior lately. Maybe once a month it will do one of the following:

1. If I twist the key to crank the starter and let go of the key, the starter will keep cranking. To make it stop I need to turn the key to the off position. I noticed this while doing some extended cranking with prior fuel system troubles.

2. Today after I turned the key to start it, the engine did not start but the starter motor sounded like it was spinning on its own for maybe 5-6 seconds without cranking the motor. Immediately I thought it was going to be #1 above so I switched it to the off position and even pulled the key out of the ignition and the starter motor was happily spinning away then stopped on its own.

After any of these incidents, it will typically fire right up the next time and I forget about it. Anyhow, what do you guys think? Starter switch or starter motor or both? My CIS is pretty dialed and fires right up when the starter isnt spazzing out.

Thanks in advance.

[john walker's workshop]

Chewed ring gear teeth grabbing the bendix teeth and not letting go is one common issue. Keeps the solenoid contacts from separating when you release the key.

[2jmotorsports]

Hi John. Here's my ring gear teeth 750 miles ago:



Would chewed teeth on the bendix side behave the same?

[MichaelSJackson]

In incident 2., the solenoid arm has not pushed the starter gear (bendix) enough to engage with the ring gear. So the motor is not the reason the starter keeps spinning, when the key is released. I'd look at the solenoid. It's not a complicated device once you have it off the starter. Easy to clean and re-lube. Also, easy to test and diagnose with just your jumper cables.

If the bolts holding the starter come loose and back-off, the torque from the starter can cause it to wobble in place. This will also allow the bendix to bind with ring gear sometimes and completely miss the ring gear at other times. But it doesn't account for the second incident where the starter continuing to run when the key is released.

[2jmotorsports]

Thanks Michael,

I think Ill pull the starter and do an inspection. I do admit that when I rebuilt the engine I never did anything to the starter other than clean it externally.