2011 bayliner flight series

bentleybent

Recruit
Joined
May 22, 2025
Messages
1
I'm working on a 2011 bayliner with a 4.3 mercruiser the starter will spin but the motor does not I seen yesterday that the crank sensor was not plugged up would that cause the motor not to spin over
 

kenny nunez

Captain
Joined
Jun 20, 2017
Messages
3,351
A good chance the starter shaft is rusted preventing the gear to engage the flywheel. Remove the starter and clean the rust off the shaft. Then lubricate it.
 

ESGWheel

Senior Chief Petty Officer
Joined
Aug 29, 2015
Messages
662
Is this a new to you boat that you are trying to get going? If yes, there are a ton of other items to address as well. Post if that is the case and are interested.

For the starter. Given you are hearing the starter motor spin, it’s likely the Bendix has failed. For the starter to get power the starter solenoid's plunger must move. This movement does two things: 1) it applies power to the starter itself and 2) it pushes out the pinion (part of the Bendix) to engage the flywheel. Here is a great video on starter operation. Link. So, if the starter is spinning it means the pinion has been pushed out to engage the flywheel. And if engine not turning over, more likely than not the Bendix has failed and thus need a new starter.

If you do need a new starter, get a marine grade. The auto starters will work and are cheaper but they are not marine certified and should never be used.

Other things that should be checked are clean, bright and tight connections.

Good luck!
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,145
I'm working on a 2011 bayliner with a 4.3 mercruiser the starter will spin but the motor does not I seen yesterday that the crank sensor was not plugged up would that cause the motor not to spin over
Is the engine fuel injected or carbureted? If carbureted then the crank sensor isn't used but comes with the engine used more so as an oil plug at the front cover...Either way, the engine would spin over while cranking the engine over to start but the engine wouldn't start up and run if the crank sensor was unplugged.

With a semi vague description, ensure nothing else is holding the engine from turning over while trying to crank the engine over to start such as does the engine turn over very slightly and stop or bounce back...If yes, the maybe a hydrolocked engine situation say from water in the cylinders or internally frozen stern drive, etc.. < Probably not the case but another option to bear in mind when diagnosing further.
 
Top