My starter often only spins and doesn't engage

[WesHeald]

I had my Delco starter motor rebuilt and just installed a new solenoid, but I still have this problem. It takes 2 or 3 tries to get the starter to engage. Anyone have any ideas?

[Dave Neptune]

Did you check the switch. If the switch either key or push button could be giving a weak signal.
Try taking a "hot wire" to the solenoid start post and see if it engages properly then.
Also be sure the battery connection is good and the battery is fully charged.

Dave Neptune

[edwardc]

I had my Delco starter motor rebuilt and just installed a new solenoid, but I still have this problem. It takes 2 or 3 tries to get the starter to engage. Anyone have any ideas?

Sounds like your pinion/bendix gear is not reliably extending fully to engage the flywheel. There are three common causes of this:

1. (most common) Dried up grease or dirt on the threads of the starter shaft and the pinion/bendix
2. Failing overrunning/one-way clutch in the bendix
3. Damage to the threads on the shaft or bendix (not common)

There's a good (if wordy) 16 minute video that explains all this:

https://www.youtube.com/watch?v=RhdSq4WOaDM

It's not Atomic-4 specific, but the principles are the same.

[Sam]

Ed's points are spot on if you hear the starter spinning but not engaging the flywheel. I had the same problem once after a starter rebuild - the bendix drive would occasionally stick in the retracted position. Took a couple of taps with a hammer to free it up to engage the flywheel. Solved the problem by taking the starter apart again and inserting two large plastic neoprene washers at the end of the shaft [aft end]. This reduced the friction between the metal parts and the bendix drive no longer "lock up" when retracted. It's been about a dozen seasons and still working.

[eastcoast]

Make sure you check the gear ring on your flywheel. On the rounded flywheel covers there is an inspection port or you can pull the cover and flywheel. Sometimes the ring can shift slightly on the flywheel away from the block and the teeth wont engage properly intermittently. I hadn't even realized it wasn't a solid piece up to that point.

I chased this issue last summer for months... including rebuilding and purchasing a starter.

[joe_db]

Did you check the switch. If the switch either key or push button could be giving a weak signal.
Try taking a "hot wire" to the solenoid start post and see if it engages properly then.
Also be sure the battery connection is good and the battery is fully charged.

Dave Neptune

I used a solenoid-solenoid to solve this issue. The AUX start button is near the engine, not in the cockpit. I don't think we are clear though if the starter is not spinning or it is spinning without turning the engine.

[Dave Neptune]

Joe, I went a little simpler. I mounted a remote switch in the engine box which I always used or starting if the boat had been sitting, when cruising rarely.

The switch was wired directly through a fuse from the battery lead on the starter. This way I could run the starter any time while working without the ignition on. When using it for starting I would just reach out and turn on the key and start from below or with the key.

Stay well!

Dave Neptune

[joe_db]

My button near the engine also works when the ignition is off. This all started because between the long run and salt water, the start button would get to where you had to try it two or three times to get a good enough contact to pull in the solenoid. Now instead of 5 or 10 amps, it only has to pass less than 1

[Dave Neptune]

Joe, during my 35 years with my A-4 I replaced the key switch twice for a weak connection. I now have the same problem with my Yanmar. Last season the "key cover" tether snapped. I kept it in the binoc box on the pedestal until someone tossed it in the trash. Now using a WD-40 cap as a cover until I can get out to get a new one. I even started it once with a screwdriver across the solenoid.
I have sprayed it and it seems to be working now. I may just replace the switch if I have any problems. Last time out it took 2 twists to make contact.

Dave Neptune