Starter On A Beta 43

[system 4-50]

Can somebody help me understand exactly what happens when you start a Beta 43?  You energise the starter solenoid which: switches power to the starter motor presumably, and throws a cog in to engage the starter ring?? How? The starter turns the engine until it fires and the speed of the engine vs the starter motor throws the cog out of mesh again?? What keeps the cog away from the ring gear with the engine fully running?  What happens if you keep the starter key turned once the engine is firing? Does it protect itself? TIA

[rawsondsr]

Have a quick watch of this

 

Edited December 4, 2018 by rawsondsr

[pearley]

There is a dirty great solenoid on the top of the starter. When you turn the key the solenoid engages and pushes the small cog on the end of the starter into engagement with the ring year. There is a roller clutch connecting the small cog with the centre shaft of the starter. When the engine fires the higher speed makes the small cog spin on the shaft. So no damage if you keep the key turned too long. 

 

Sometimes the clutch will fail and the cog stays in engagement destroying the starter motor. 

 

Often with a failed starter you can turn the key and hear a click, this being the solenoid. Sometimes when this happens with a fully charged battery people will hit the starter to make it engage. Sometimes this will work as the earth path for the solenoid windings is through the starter brushes and, if they are worn, hitting the started makes them make better contact. Try this with a starter with permanent magnets rather electro magnet coils will also destroy the starter. 

[system 4-50]

Thank you.

[Chewbacka]

1 hour ago, pearley said:

There is a dirty great solenoid on the top of the starter. When you turn the key the solenoid engages and pushes the small cog on the end of the starter into engagement with the ring year. There is a roller clutch connecting the small cog with the centre shaft of the starter. When the engine fires the higher speed makes the small cog spin on the shaft. So no damage if you keep the key turned too long. 

 

Sometimes the clutch will fail and the cog stays in engagement destroying the starter motor. 

 

Often with a failed starter you can turn the key and hear a click, this being the solenoid. Sometimes when this happens with a fully charged battery people will hit the starter to make it engage. Sometimes this will work as the earth path for the solenoid windings is through the starter brushes and, if they are worn, hitting the started makes them make better contact. Try this with a starter with permanent magnets rather electro magnet coils will also destroy the starter. 

Certainly some car starter motors don’t have a clutch mechanism and the starter motor will only disengage when the key or start button is not in crank position.  However the starter motor will run at engine idle speed for a while before it is damaged.  

 

Edited December 4, 2018 by Chewbacka

[pearley]

3 minutes ago, Chewbacka said:

Certainly some car starter motors don’t have a clutch mechanism and the starter motor will only disengage when the key or start button is not in crank position.  However the starter motor will run at engine idle speed for a while before it is damaged.  

 

In 40 years as an auto electrician I never came across a pre engaged starter that didn't have a clutch but plenty of starters on older vehicles with separate solenoid. But the OP was talking about his Beta 43. 

[Boater Sam]

Worth mentioning that there are 2 windings on the solenoid, one to pull it in and one to hold. The pull in one returns through the starter motor so drops off once the solenoid engages the starter.

We used to get the odd Granada Auto that held its starter in mesh after starting  With a rev of the engine they used to spin all the motor copper windings out of the armature with the centrifugal force, looked very interesting after.

Why just Grandad Autos I never figured.

[Sir Nibble]

13 hours ago, pearley said:

In 40 years as an auto electrician I never came across a pre engaged starter that didn't have a clutch but plenty of starters on older vehicles with separate solenoid. But the OP was talking about his Beta 43. 

I could have written that word for word.?