Battery Size for a 91 Mercruiser 4.3L

[toddnfarmeriboats]

I suspect that my battery may be too small to run my hydraulic trim pump. Sometimes it will work and sometimes it wont even when the motor is running. I can hear the solenoid click but the trim motor wont always come on. Trying to go up is usually what wont work.<br /><br />I dont think the battery in it is a marine battery. It is a Advance Auto "Economy" brand 24-2 with 525 CA and 420 CCA with a reserve of 70. I dont have any extras on the boat except a manual switch bilge pump.<br /><br />Questions:<br />Could the battery size have anything to do with the trim motor coming on?<br />What size Battery should I be using?<br />How do I find out what horse power the boat motor it is?<br /><br />Motor info<br />91 Mercruiser 4.3L<br />Engine OC861547<br />Transom OD318372<br />Drive OD314345<br /><br />Thanks for any assistance.

 

[Don S]

Re: Battery Size for a 91 Mercruiser 4.3L

Any size 24 battery will work for start the 4.3 just fine. Best to have a disignated "Starting" battery instead of trying to use a deep cycle battery.<br />Using a deep cycle battery for starting will shorten the life of the Deep Cycle battery due to the high draw.

 

[toddnfarmeriboats]

Re: Battery Size for a 91 Mercruiser 4.3L

One thing I am trying to find out is could the battery amps make a difference in the trim motor coming on.

 

[Don S]

Re: Battery Size for a 91 Mercruiser 4.3L

Hard to say, what is your problem, that would be a better quesion than just beating around the bush without anyone knowing what you are driving at.

 

[waterone1@aol.com]

Re: Battery Size for a 91 Mercruiser 4.3L

To answer your question....NO. Your trim pump most likely has a 90 amp fuse on it....it will work with under 90 amps available. Most likely you have a bad relay (solenoid) or bad pump motor. Keep in mind, that the "up" circuit goes through the trim limit switch on the drive, that is notorious for failing. In this case I would have to say 90% that this has nothing to do with your battery.

 

[toddnfarmeriboats]

Re: Battery Size for a 91 Mercruiser 4.3L

Thanks for the info guys.