Fiat 126 Chat => Fiat 126 Mechanical Problem Solving => Topic started by: Iffy650 on July 08, 2021, 01:56:11 PM

Title: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 08, 2021, 01:56:11 PM
Hi,
I bought a reconditioned electric starter motor in england but didnt and test it before fitting to my air cooled '89 126. The damn starter spins but doesnt engage with the fly wheel. Took it off and tested to find that the toothed cog produces no torque when powered up. It spins and moves to the correct position but when I held the cog with a big screwdriver the shaft just spins doesnt lock the cog on and drive (the flywheel)
Im in Australia and new starter motors are rare/stupidly expensive. I noticed that Ricambio sell replacement bendix for the starter motor for 16 quid and I'm curious if anyone knows whether replacing the bendix in my "reconditioned" starter would fix this problem?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Pete126 on July 08, 2021, 08:47:15 PM
Have you checked that the solenoid is throwing the dog in?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 09, 2021, 01:27:17 AM
Thanks Pete, yes its throwing the cog into the correct position. Then I did the test of holding the dog with my biggest screwdriver to see if it would give me any torque but the dog held and the shaft just spun (i was getting no torque on my screw driver)
Cheers
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 11, 2021, 12:52:20 AM
Hi Pete,
Do you reckon replacing the bendix in the starter motor will fix it?
Cheers
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: ChrisRLewis on July 11, 2021, 07:00:01 AM
Have you tried pulling the lever on the starter motor manually to rule out the problem of the bendix not engaging properly?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 11, 2021, 04:12:37 PM
Thank you Chris,
Its an electric starter. Didnt know that it has a lever? The solenoid moves the lever doesnt it?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: ChrisRLewis on July 11, 2021, 11:36:43 PM
The older type starter motors for the 126 have a lever which is cable operated (see photo), so you don't have this type?
What happened to your old starter motor? could you swap the bendix/clutch over to see if it resolves your problem?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 12, 2021, 03:18:47 AM
Thanks Chris,
I've got the newer electric starter with solenoid. Unfortunately the starter motor was missing on the 126 Im restoring. I bought a reconditioned starter from a guy online in england but when i fitted it and tried starting it just spins and doesnt engage the flywheel. The recon starter looked in really good nick so i was thinking of buying a new bendix from ricambio or axel grest and fitting that cause 2nd hand or new starters are hard to get/very expensive in australia. Do you reckon a new bendix will fix it?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: ChrisRLewis on July 12, 2021, 02:41:35 PM
It's a job to say if a new bendix will cure your problem. How are the teeth on the flywheel?
How much is the shipping charge of a new bendix to Australia?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Minijohn on July 12, 2021, 10:15:50 PM
Hi Iffy650

If I understand you correctly, this is very simple.
If the shaft rotates but does not turn the cog, it must be the bendix that has an internal fault.
The cog must turn with the shaft. It may slide along to the end first, but once it reaches the end it must turn.

On your starter, if you turn the cog by hand - does the shaft turn?
If not, then you need a new bendix.

I hope that helps
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 17, 2021, 08:36:22 AM
Hi Minijohn,
Thanks for replying.
I've been testing my starter on my bench. I can turn the cog by hand in the direction shown by the arrow  on the end of the solenoid (anti-clockwise when looking on the end of the starter see photo) but by doing that it does not turn the shaft. If i turn it the opposite direction it does turn the shaft.
Is this correct?
Cog does spin to the end when i connect power from battery.
I also tested the solenoid on its own and it moves the cog to the end.
My conclusion is the the starter has tested ok and is working fine but im not sure whether the cog not turning the shaft by hand in the anti-clockwise is causing my original problem - starter spinning and not cranking the flywheel?
Hope you have a chance to reply, cheers
(https://i.postimg.cc/4HQLwc1b/20210717-153316.jpg) (https://postimg.cc/4HQLwc1b)
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 17, 2021, 10:15:57 AM
Teeth on the flywheel look good
(https://i.postimg.cc/rd8Wkf75/20210717-160245.jpg) (https://postimg.cc/rd8Wkf75)
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: ChrisRLewis on July 17, 2021, 01:21:36 PM
Looks like the only option would be to replace the bendix, at least you will have a spare one if you have the same problem.
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: ChrisRLewis on July 18, 2021, 12:25:35 AM
This may be of help to your problem.
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 18, 2021, 05:31:46 AM
Thank you Chris
That is very helpful, time to strip my starter motor to check the bendix.
Cheers
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Minijohn on July 19, 2021, 10:18:41 PM
Hi Iffy650
You said...
I can turn the cog by hand in the direction shown by the arrow  on the end of the solenoid (anti-clockwise when looking on the end of the starter see photo) but by doing that it does not turn the shaft. If i turn it the opposite direction it does turn the shaft.

That sounds like it's working fine because to start the engine the shaft drives the cog, and when the engine is going faster than the starter, the cog freewheels otherwise the engine would drive the starter motor. The cog will never drive the shaft.
Sorry, reading my previous post again it's a bit ambigous. The bendix allows drive in only1 direction, it freewheels in the other.

In your original post you said...
It spins and moves to the correct position but when I held the cog with a big screwdriver the shaft just spins doesnt lock the cog on and drive (the flywheel)
The only thing that takes the drive from the shaft to the cog is the Bendix so that indicates the Bendix is faulty.

Can you post a photo of your bendix in situ - I wonder if it's been assembled incorrectly?

Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Iffy650 on July 24, 2021, 02:42:47 PM
Hi,
I was happy with how the starter motor tested on my bench so I put it back in and tried starting. After a couple of times of spinning without engaging it decided to engage and started!
Sometimes it engages sometimes not but it always spins. So, now I reckon it must be an intermittent electrical fault which might be to do with the ignition switch.
Anyone had a similar problem with ignition switch not engaging the flywheel, e.g.solenoid not getting power?
Title: Re: Reconditioned Electric Starter Motor: Spinning but Not engaging
Post by: Minijohn on July 24, 2021, 03:31:27 PM
You can bypass the ignition switch....

Connect a wire from the positive terminal on the battery.
Touch the other end of that wire to the small terminal on the solenoid.
That will activate the solenoid which in turn will turn the engine over.
(The engine won't start unless the ignition is switched on but should turn over)

If that still gives the same intermittent engagement, I'd check battery terminals, engine earth strap, solenoid connections. Also battery voltage - is the battery any good?

Your original comment bothers me though...
It spins and moves to the correct position but when I held the cog with a big screwdriver the shaft just spins doesnt lock the cog on and drive (the flywheel)
You shouldn't be able to stop the cog turning when the starter is spinning - that would indicate the bendix is slipping.

Good luck
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