1999 Mercruiser 3.0L XL with est ign

[kramerpage]

Well another interesting issue with my Mercruiser. I have been buying a new battery every year for four years. Inexpensive ones from Advance Auto and I just figured it barley cranked due to the battery had only 500 CCA. So this year I got an 850CCA battery and the same issue happens, although each year its getting worse. This year the motor would not rotate. I only hear one click and that's it. I read the voltage and it was 13V on a digital meter. I cleaned battery conductors with a brush with no luck. Now Im thinking I got a bad new battery so I jump it to my car with the same result. I got a sledge hammer and beat the starter (wood handle side). Now It begins to slowly turn. Like ever so slowly. Not enough to start. I sprayed starting fluid in carb and let car continue to run while I took a 10 minute break. Came back same thing. I finally got enough rotation to fire the motor and she ran great. Tried a restart. Same issue. Used a heavy set of jumper cables and ran the negative from battery to engine ground stud and positive from battery to starter thinking the wire set conductors may be faulty. Same result. Cranking so slow it barley starts but is starting. The starter sounds strange. Not a metallic sound but a low~~grumble sound. I would like to pull starter this weekend and run on bench. Any suggestions? Thanks

 

[Bt Doctur]

Think its time to have the starter checked/rebuilt/replaced.Also check the neg cable attachment point on the motor. Battery cable could also be bad internally.

 

[glenn property of pam]

The fun thing is when the starter is on the bench it may run like a scolded dog as there's no load.
Most starters have more than one set of brushes and a field coil. If the field coil is partly burnt out, solenoid has burnt contacts or one set of brushes are bad the starter will still run on the bench but wont crank the motor.
As hitting the starter seems to work that sounds like the starter needs rebuilding.

 

[kramerpage]

I removed the starter. Found that the brushes were worn. 1 of the three brushes was still good. So I had contact from one brush. I purchased a new starter and the boat starts great. This must have been going on for a total of 4 years now. I only use the boat twice a year. The starter was 236 dollars and a pain to get to the two mounting bolts.