Starter spins but no crank

[Roger K Sterling]

I’m a newbie to boating. Batteries are chartered and when I turn the ignition I hear the starter spinning but no crank. Any suggestions?

 

[Ididntdoit]

sounds like the bendix is not engaging the starter to the flywheel - most people just replace the starter....its likely you have some corrosion on the shaft and it needs to be cleaned and lubed.

 

[scoflaw]

starter solonoid located on starter. Pull your starter and also check the teeth on the ring gear

 

[Thornton69]

Splitting hairs, but the starter motor will not spin if the solenoid does not first engage.
When you say "crank", do you mean the engine will not start or it is not rolling over with the starter?

 

[Roger K Sterling]

All I hear is a spinning noise from the starter

 

[Halfhitch]

Either the bendix is bad, it can be replaced, or there are missing teeth on the flywheel ring gear and the last time you turned it off, the spot with the missing teeth stopped right at the starter. Look it over while your mate hits the starter. Not rocket science.

 

[dwna1a]

Bad bendix, give it a tap or two with a lightweight hammer. See if it will come loose. Still, replace. Look for any broken teeth on it or the flywheel

 

[Steve255AJ]

I've had this problem. It's an easy fix, most likely.
The marina where I kept my boat a the time said I needed a new starter.
I was skeptical, so I removed the starter, not easy but I did it.
Took it home, took the gear of the shaft, wire wheeled shaft and gear.
Cleaned everything up and lubricated. Bench tested with a 12V supply.
Now the gear moves as it should.
installed the starter and turned the key, engine starts perfectly..
Good luck.

 

[b_arrington]

A bit of an old thread, but not everyone understands the mechanics of an engine starter.

• There is a toothed flywheel of fairly large size on the engine. When this spins it allows the compression cycles to start.
• The starter functions by engaging the flywheel. It has a gear on the end that's about an inch or so in diameter. The high torque starter motor spins the flywheel fast enough to start the motor.
• But, the engine (and flywheel) will run faster than the starter motor. If the starter gear were to be permanently engaged to the flywheel it would be damaged.
• This is where a Bendix gear comes in. The starter is mounted so that at rest the gear sits to one side of the flywheel gear, usually behind it. The gear sits on a movable shaft. When the starter is engaged, gearing on the shaft (the Bendix) forces the shaft (and the small gear at the end) to extend out from the end of the starter assembly. The starter gear engages with the flywheel to turn the motor. When power to the starter is cut the Bendix gear retracts the starter gear into the body of the starter so the motor can run without interference.

If you've ever engaged your starter with the engine running and heard that awful grinding noise, that's the starter trying to push it's laterally and trying to engage the flywheel.

Now, what folks are talking about is the shaft on the Bendix could be stuck so the starter spins but can't extend out to engage the flywheel. Tapping it or lubing might loosen the stuck Bendix gear / shaft.

The other thing is that a tooth/teeth can break off the flywheel, creating a dead zone where there are no teeth for the starter to engage. If that dead spot comes to rest where the starter gear sits, there's no teeth for the starter to engage. You need a new flywheel in that case. The flywheel itself isn't that expensive, but it's a lot of labor to get at it. We had a GMC Acadia that had a couple teeth missing, and it caused dead spots. The starter would just spin.

 

[The Bill Collector]

Bad bendix, give it a tap or two with a lightweight hammer. See if it will come loose. Still, replace. Look for any broken teeth on it or the flywheel

I wondered how many posts I would have to scroll down before someone would say "hit with a hammer" !!! LOL (that's what I do)

 

[scoflaw]

A bit of an old thread, but not everyone understands the mechanics of an engine starter.

• There is a toothed flywheel of fairly large size on the engine. When this spins it allows the compression cycles to start.
• The starter functions by engaging the flywheel. It has a gear on the end that's about an inch or so in diameter. The high torque starter motor spins the flywheel fast enough to start the motor.
• But, the engine (and flywheel) will run faster than the starter motor. If the starter gear were to be permanently engaged to the flywheel it would be damaged.
• This is where a Bendix gear comes in. The starter is mounted so that at rest the gear sits to one side of the flywheel gear, usually behind it. The gear sits on a movable shaft. When the starter is engaged, gearing on the shaft (the Bendix) forces the shaft (and the small gear at the end) to extend out from the end of the starter assembly. The starter gear engages with the flywheel to turn the motor. When power to the starter is cut the Bendix gear retracts the starter gear into the body of the starter so the motor can run without interference.

If you've ever engaged your starter with the engine running and heard that awful grinding noise, that's the starter trying to push it's laterally and trying to engage the flywheel.

Now, what folks are talking about is the shaft on the Bendix could be stuck so the starter spins but can't extend out to engage the flywheel. Tapping it or lubing might loosen the stuck Bendix gear / shaft.

The other thing is that a tooth/teeth can break off the flywheel, creating a dead zone where there are no teeth for the starter to engage. If that dead spot comes to rest where the starter gear sits, there's no teeth for the starter to engage. You need a new flywheel in that case. The flywheel itself isn't that expensive, but it's a lot of labor to get at it. We had a GMC Acadia that had a couple teeth missing, and it caused dead spots. The starter would just spin.

 

[scoflaw]

Not a flywheel it's called a ring gear

 

[b_arrington]

Not a flywheel it's called a ring gear

OK. My mechanic call it a flywheel.

 

[scoflaw]

ring gear attaches to the flywheel.

 

[dwna1a]

Scoflaw is correct, ring gear. I used the hammer trick on my old Chevy Nova. It won’t continue to work. You must replace, the bendix spring is getting weak

 

[Nater Potater]

ring gear attaches to the flywheel.

Oh, the Ring Gear attaches to the, Flywheel
The Flywheel connects to the, Crankshaft
The Crankshaft connects to the, Oh nevermind...

 

[Blueone]

Bad bendix, give it a tap or two with a lightweight hammer. See if it will come loose. Still, replace. Look for any broken teeth on it or the flywheel

LOL…. an IT guys version of control alt delete…. Hit it with a hammer

 

[scoflaw]

And for some reason the wack does the trick

 

[Blueone]

And for some reason the wack does the trick

So does control alt delete

 

[dwna1a]

You can laugh. I’ve seen pics of my dad standing in front of one of his birds holding a rubber mallet. I asked him why once, he said in Korea the birds would get so cold it took a wack of the nose to get the turbine to spin up. I don’t know if it’s true, but that is his story.