Unusual starter motor problem.

[Andy2uk]

Hi All...

I replced the starter motor on my 2.1 DJ last year with an ebay N.O.S . starter motor..

but twice now i have been stuck with the following problem..

When trying to start the motor the starter spins up and works like normal... however it fails to stop spining... it has disengaged from the motor.. and is no longer turning the engine over... but it continues spining.. ,, as a result i have to disconnected the battery and whack the crap out of the starter with a mallet..

What i dont understand is if the solinoid is getting jammed "ON" , then howcome the gear is not engaged with the flywheel.

Is this something i can strip and repair ? as all resources i have found on the internet are more the brushes and motor rebuild.. with the solinoid just being replaced.. ??

Andy

[Aidan]

it's the electrical contact part of the solenoid welding itself to the cap, the mechanical bit has let go probably the engagement dog is sprung - I guess you pulled the trigger wire off and it still ran before gentle persuasion was used

[mm289]

probably as Aiden said.

Solenoid does two things:
1. fires the starter cog forward into the flywheel teeth by creating a magnetic force that sucks the plunger in and pulls the engagement level

2. switches the 12v feed from the battery across to the starter motor to turn the shaft.

so yours is doing 1 & 2 but when you release the ignition key it is only "undoing" 1 i.e. disengaging the cog but not disconnecting the feed to the starter motor.

Solenoids are not generally rebuildable/maintainable unless you know your way around electrics. The solenoid is held together with 2 screws but also by the wires that are soldered to the terminals - to strip you have to unsolder these IIRC and then re-solder on re-assembly.

starter not under warranty I suppose?

MM

[Andy2uk]

Thanks for the reply ....

No warrenty for me...as it was an Ebay N.O.S starter...

Id guessed it was the terminals sticking together.. i guess it would be an easy fix for someone who overhauls starters as its not the motor itself.... but my local guy has now shut up shop..

i will whip it off at the weekend and take another look . maybe i can get some contact lubricant on the switch contacts .

thanks all.

[Aidan]

if you can remove the solenoid and stick it in the post I can get my local gut to rebuild it with a new correct cap; should be held on with three phillips head machine screws, two screws for early Aircooled starters

[mm289]

oh err, if thats the case I have the wrong starter on my DJ

solenoid is held to starter with two straight head screws and top of solenoid held on with 2 straight head screws

[Aidan]

I may be wrong on the number of screws/bolts - I haven't got one in front of me to check - but looking at etos it says three torq socket head machine screws M5 x 33

[kevtherev]

my motor has three M5's Aiden

Oh.. and I thought solenoids were just a gate to allow big current through and the starter threw the dog out with torque, not the solly?

[Aidan]

there's a lever at the bolt end of the solenoid in the starter housing which the end of the solenoid pulls with a reciprocating action pushing the dog out into the ring gear against the spring which returns it swiftly once the starter position at the switch is released, this spring pressure helping to disengage the solenoid's internal connections, which isn't happening here, maybe the spring is broken inside the starter

[mm289]

I've got the starter on the bench at the moment, from memory its a bosch unit, will look at the part no if I can find it.

From memory..... I think I have seen starter motors with cogs that are "thrown" into the flywheel when the starter kicks in, generally on a screw splined shaft IIRC. (I think this is a very old design - must of been reading those history books Kev )

[kevtherev]

yeah well they never suffered your problems...progress huh?