How can I repair starter pull on McCulloch Cabrio 310?

The starter pull will not engage with the notched shaft-head. There is a small plastic cam that picks up a notch in the shaft-head, and that retracts when the shaft is spinning - but there must be a spring-clip or something that pushes it away from the reel-holder? Your assistance with how to repair it and where I can get any parts I need would be appreciated