I'm yet to start my engine but when I try to make it spin with the starter it works OK but the bendix does not disengage. I think that when the engine start the bendix should disengange, but if the engine does not start I don't know.

Been here - took over a year of on / off looking into the problem to get the solution. Eventually, it was my dad who fixed it by being a pain and doing obvious things like counting ring gear teeth.

The starter will only disengage when the engine fires - the engine spins faster than the starter forcing it back up the bendix. (one of) the issues i had was the actual start motor pinion was a bit knackered. It was only when you took it apart you found bits inside broken. New pinions can be bought and its easy to repair.

u2u me for more details (will take a while to reply tho - not at home)