Mercruiser 3.0l starter motor problem.

[Simoniz]

Hi All, been a while since I was on here as my boat has been running sweet, but its just gone back into the water after the winter break and now Im having a bit of trouble.

At first the battery (which has been off the boat all winter and regularly charged) would hardly turn the engine over, so I recharged it and tried again - no better. The off load voltage was only 11.6v and the battery was 6 or 7 years old so Ive now bought a new battery and fitted it.

First try the battery spun the motor in a lively fashion, but then the engine stalled (too cold) so I tried to start it again. This time there was just a click in the engine bay, so even though they had been fine the first time, I checked that the battery terminals were OK.

They were (all electrics work fine and the electric trim works well), but on trying again, theres absolutely nothing when I turn the ignition key to the start position. I tried running a jump lead from the battery positive to the terminal after the solonoid on the starter and the started turns just fine, although the bendix does not engage with the ring gear on the engine flywheel but I suspect that this is because I didnt have the ignition key held in the fully clockwise position (I couldnt reach both the engine area and the ignition key and was working alone).

Im thinking its either the starter bendix stuck, or the solonoid which is bust, or possibly it could be the interlock which prevents starting the engine with the boat in gear.

Any tips and pointers as to how to troubleshoot this would be greatly appreciated!

Boat is a 2001 model Bayliner 175 with Mercruiser 4 cal, 3.0l 135hp motor.

 

[Bondo]

so Ive now bought a new battery and fitted it.

Ayuh,..... Did you polish the posts, 'n clean the connectors,..?? even new, there's a corrosion film on 'em,.....

although the bendix does not engage with the ring gear on the engine flywheel but I suspect that this is because I didnt have the ignition key held

Nope, it's because you should jumper to the top big post, 'n the tiny inner post to engage the starter,......

Any tips and pointers as to how to troubleshoot this would be greatly appreciated!

Clean ALL the connections, Both battery posts, connectors, Both of the other ends of Both cables, 'n the connections on the solenoid,.....

 

[Simoniz]

Cheers Bondo san!

Well I cleaned all the connectors but it didn’t really help so did a bit of trouble shooting with the aid of the manual and a multimeter and tracked it down to the slave solenoid.

Always throws me when I replace something and something else which is unconnected to it goes wrong at the same time.

 

[harringtondav]

Cheers Bondo san!
Always throws me when I replace something and something else which is unconnected to it goes wrong at the same time.

It is said "trouble comes in threes" ....whoever coined that must have been a boater.