Starter motor problem

[penryar]

Got a problem with my 1979 Spider 2000, when you twist the key, the starter solenoid activates, the starter whirrs, the engine turns over for a second or 2 then then stops turning with the starter motor still spinning.
The pinion gear is becoming disengaged somehow from the starer ring on the flywheel.
Has anyone got any advice on what could be up. I've had the starter off (no easy job) and on the bench cleaned up, and it all seems to be functioning correctly.

Steve

[Mikey G]

At a guess with the age of the vehicle the starter is not a pre-engaged unit? Sounds like the pinion is not being thrown in enough and is disengaging, worth checking the pinion moves freely on the screw on the end of the starter shaft.
If the unit is pre-engaged then there could be a problem with the solenoid on the top of the starter again not throwing the pinion out enough.

HTH

[steve_d]

If the starter is not pre-engage i.e. when it spins the pinion is thrown down the shaft by a helix then it is most important that the pinion, spring, and all the other bits are clean and free moving. They must not be lubricated in any way unless you have access to some graphite dust. Any oil or grease will just pick up all the clutch dust and jam up in short order.

There is also the possibility that the ring gear has worn at the compression point and the pinion is not gripping. If this was the case then your description of the problem would have included the horrible grating sound.

Steve

[leorest]

steve_d said:

...unless you have access to some graphite dust...

A soft pencil lead contains graphite!

[penryar]

Thanks for all these tips, the starter is a pre-engage type, current is only passed to the motor itself when the solenoid is fully activated. I'm beginning to think that the problem lies with the fork used to push the pinion gear onto the starter ring. Its a plastic fork so after 27 years its bound to be worn somewhat.

Looks like i'll be back under there tomorrow.

Cheers

Steve