Solenoid ? problems

[bernard]

I have just had primary cases off and on rebuilding am having difficulty with starter solenoid. Starter motor spins and solenoid trys to throw the gear out but fails. The pin in the cup falls out. On attaching battery earth I got heavy sparking on a couple of attempts. Have I assembled something incorrectly?
I suspect the solenoid. Any thoughts or servicable solenoids appreciated.

[lambo]

Have you put the spring back in the correct position?easily put back wrong when you are pushed to get it back together

[bernard]

That seems like a real possibility. I've been tired . Will check that tomorrow.
I was just about to order a new solenoid. I'm hoping you saved me a few quid. Thanks.

[bernard]

Thank you Lambo.
I did indeed assemble with the spring in the wrong place.
What a bloody tedious job it is doing it the right way. The last time I did that job was over twenty years ago and it has been the source of back problems ever since.
Many thanks for the advice