3.0 merc sputters when adj. trim.

[pfd]

I have a 1987 searay with a 3.0 merc/alpha I OD. I just got the boat last year and was glad to see it started after the winter. My problem lies with the electrical sys. I think???<br />It runs fine on land... doesn't like the water.The motor runs fine but At higher rpms and when the trim is ajusted, the motor sputters and losses power. The voltage drops from 14 to 12. I haven't really mess with anything yet but I'm assuming that I have a short somewhere that is draining in the water. I have the old battery and when in the water it doesn't hold a charge but on land it seems fine. Advice would be greatly appreciated.

 

[tommays]

Re: 3.0 merc sputters when adj. trim.

the trim pumps are high pressure and draw around 100 AMPS when its pushing against the prop to trim the drive<br /><br /> so if your battery is weak or you have a alt problem the voltage drops to low for the ignition system to give good spark and the motor sputtters<br /><br />it could be the pump but if the battery is not holding a charge its a good place to start<br /><br /> http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf <br />your drive and trim pump<br /><br /> http://www.boatfix.com/merc/Servmanl/13/13covr2.pdf <br />some things on you motor depends on the year<br /><br /><br />tommays

 

[Trent]

Re: 3.0 merc sputters when adj. trim.

Does this engine still have the orginal type of ign. setup? As in points and condensor? Or has it been converted to electronic ign.