78 black max 150 hp just died. battery dead

[m.qualls89]

I went out the other day and it was dark. Boat ran fine except on the way in i was just idleing along i decided to kick it for a minute to wot. It went about 150 feet and just died, it was like hitting a wall i stopped so fast. Tryed to start it and battery was dead. Could it have been that at idle it wasnt charging enough to run the lights radio and boat? I tryed to start it yesterday with no luck but i didnt mess with it long. I had a wiring issue from my last mechanic but i thought i had it corrected. Any ideas of what to look for tonight?

 

[Georgesalmon]

Re: 78 black max 150 hp just died. battery dead

That motor has about a 9 or 10amp unregulated charge system. Should be plenty to run a radio and lights. Could be a bad battery, could be a lot of other things. Stator, rectifyer, coroded or loose wiring connections at the battery. I would start by charging the battery and just checking all wiring connections and cleaning them. Then check voltage at battery, start engine with muffs on. The voltage should be a little bit higher when running than it was before running. If it is higher running your charge system is probably OK. Still have a problem? Have the battery checked.

 

[Chris1956]

Re: 78 black max 150 hp just died. battery dead

It is likely a bad battery, shorted rectifer or bad wiring. Charge the battery and put a voltmeter on the battery and see if the motor charges. Test the rectifier to see if it is shorted to ground. With the battery charged, connect the ground battery cable. Now put an ammeter (Multimeter on 10ADC setting) in series between battery positive and motor positive cable. See if you have a drain, with everything shut off.

 

[m.qualls89]

Re: 78 black max 150 hp just died. battery dead

now that's the forum is back up I can post my findings. I charged the battery and it would not start only turn over so I cleaned the spark plugs as they were wet.it still would not fire so I unhooked the gas line and pump a few squirts of gas out with the primer bulb. after that it started but ran really rough even at wot it barely would run. after about a minute it started to pick up and eventually began to run correctly. I guess I have water or trash in the fuel. as for the dead battery I don't understand that because it is charging and the battery is holding a good charge.