mercruiser 3.0 starting problems

[buckeyedan11]

My boat engine will not start cold unless jumped. I have replaced the battery, cables, and starter and I still have the same problem. It seems like the starter just doesn't turn the engine fast enough to turn it over. Once jumped, starts ok for a little while. But then the same problem a little while later. any suggestions?

 

[Don S]

Re: mercruiser 3.0 starting problems

Have the batteries load tested.

 

[buckeyedan11]

Re: mercruiser 3.0 starting problems

The batteries are brand new and fully charged.

 

[Don S]

Re: mercruiser 3.0 starting problems

Bad cables-Loose cables-Corroded cables. (Both positive and/or negative)
Defective battery switch
Defective starter

All are possibilities