Need a little clarity of your problem,does the handle pull everytime, and the game will not start (only 75% of the time), the spin switch and handle switch are in parallel, it could be a mechanical problem or a electrical problem. since there are no pictures of your machine, I assume you don't have a bill acceptor unit on the machine, if not , then you can push up on the solenoid with your finger and this will allow you to pull the handle down, watch as the handle approaches the full down position, it will come in contact with the switch arm lever, when this lever is depressed it will activate the switch, I have seen this lever get bend where as the handle will never come in contact with it, you can bend this back in position. usually there is a reason it is bent out of position, check all the handle parts for broken parts. you can check it electrically by getting into the test mode, go to the input tests number 16, this should unlock the solenoid and when the handle is pulled it will change from a zero to a 1. check out the flip cards in the front section of the S+ topic.
Hope this Helps.
Jim