When I attempt to start my Mercruiser 4.3 litres, sometimes the starter does not turn over on the first or second attempt. Once it turns over, the engine starts fine. Not sure whether the problem is in ignition switch with key or whether the starter is suspect. Is there a safety contact in throttle/shifter which prevents starting in gear.<br /><br />What should I look/listen for to try and diagnose the source of the problem?<br /><br />thanks for any help