MF294-4

Member
What is different about new starters? The old starters that I am used to is so big and heavy that you can barely lift them. The new ones on tractors now days looks like you could put one in your lunch bucket.
 
The older ones were direct drive. In other words the rotor of the motor was connected directly to the bendix. That being the case the motor has to be large enough to develop both the speed and torque required to directly spin the engine.

The newer ones I assume your talking about are have a gear reduction. In them the motor itself is smaller, and spins a lot faster. Instead of driving the bendix directly the motor instead drives it through a gear reduction. This enables the starter motor to develop more torque in a much smaller package.
 
And having permanent magnets instead of field windings makes them very fragile!

You don't want to drop one and gone are the days of giving it a whack with a hammer to get one more start when the brushes are gone!

The magnets are bonded to the inside of the case and are easy to break.
 
Agree with the others, gear reduction and super magnets. I wonder if the permanent magnet ones can handle reversed polarity.
 
"I wonder if the permanent magnet ones can handle reversed polarity"

NO,,,Unlike an electromagnetic field starter motor, they would turn the opposite direction if polarity were reversed. Their North/South Magnetic Polarity is fixed if they indeed use permanent magnets.

John T
 
Lighter motors - less friction due to lower viscosity oil. Short crank times due to electronic fuel injection and high energy spark. the general attempts to lighten up everything due to fuel economy restrictions.
 
Another thing... timing is precisely controlled and they don't have to be made as heavy/strong to withstand an occasional kickback... ONE example... small block Chevies... since their inception, 'til the introduction of EFI, they had a heavy starter with a brace from the front end to the engine block, and would still occasionally break a drive end endbell.

By the late 80's, that was a thing of the past, and later the starters were greatly lightened, including the drive end, and I can't recall seeing a broken one.

(I have a 1978 medium truck in the shop right now for some PS repairs, and it rattles and "kicks" when cranked. LIKELY, the mech spark advance is stuck... gonna have to take a look at that.)
 

EPA mileage regulations. Reducing vehicle weight.
Used to be a vehicle would need a starter, battery and alternator every 2-3 years. V fan belts every year.
Now people whine and moan about modern vehicles with the original starter, alternator and fan belt at 100,000 miles at 10yrs of age.
 
Yet another factor that has not been mentioned is the improvement in electrical insulation in the past several decades.

Insulation materials have improved, allowing more copper to be wound in the same area than in years past. This, in conjunction with computer designed windings allows smaller and/or lighter windings, resulting in weight/size reduction for similar performance.

This from a long since moved on motor designer....

Dean
 
B&D I hope you know you are talking about me. Will try not to gripe so much as long as I can get reasonable starters and alternators that are not made in China.
 
Make that VERY easy to break. Love it when the old man banged on a new style lawn mower starter with a hammer. No the starter WAS fine, the connection on the battery was crap. Needed a new used starter afterwards!
 
One of the best steaks ever was from a bet that I could not make a reversing winch out of an old chev starter. Using only one-half at a time I isolated the field terminals. Reverse on one-half was then accomplished bring the postive feed out the front of the case.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top