1984 Mercury 115 Generator

[kxracedad]

I assume it has one

Last night we were coming back from fireworks, I had fully charged the outboard battery earlier in the day (boat isnt used much anymore). The battery is only a couple years old.

I had started the motor several times last night, then at the end of the fireworks had about a 30 minute boat ride (10 mph or so) back to the dock. Everything was fine until we got close, motor died and no juice to start it. On the way back, I had the dash lights on and stern light (bow light runs off trolling motor batteries, had to "rig" it a couple years ago).

I assume this thing has a generator, does it sound like this is the problem? Is there a voltage regulator built in?

also, when running full throttle and hit a big wave the motor will drop rpms and have a difficult time recovering...can this be related?

 

[kxracedad]

Re: 1984 Mercury 115 Generator

nobody knows anything about this?

 

[arsenalpsu]

Re: 1984 Mercury 115 Generator

this motor has a stator, and yes it charges the battery when everything is working correctly. When you hit WOT and have nothing on pulling power, it will boil your battery. These motors use the battery as a power regulator, extra energy is dumped into the battery or the voltage would get way to high and fry your electronics. As your batter is a few years old, is it a "maintenance free" battery? If so i bet you ran it dry, if not than open up the cells and check if there is any water in there. If any are dry you'll need a new battery, if any are low you'll need to fill them with distilled water.

OK so she didn't start, your battery could have been dead as stated above, you may have fried your rectifier, if so then it would not charge the battery OR this could have been your problem all along if your battery is ok and just needs to be recharged. This is an easy replacement, the rectifier turns the AC voltage from the stator to DC, w/o it no voltage goes to the battery. If you have a good battery, try to get her to turn over, if nothing happens when you turn the key it could be your starter or the sylinoide.

For the your issue when you hit waves, it could be loose connection in any number of parts. You need to get an OEM manual and start reading.

 

[kxracedad]

Re: 1984 Mercury 115 Generator

I took the battery home and charged it, going to head back today to see if it starts.

Seems like I read somewhere that if I test the voltage of the battery with the motor off then test it with the motor on it should read more voltage indicating it is being charged. If I get the same or lower, is the rectifier the place to start? The stator was replaced a couple years ago while on an out of state fishing trip by some shop in AL.

When I brought the battery home two of the cells were right at the plates, I refilled them and topped the others off.

 

[arsenalpsu]

Re: 1984 Mercury 115 Generator

if it's not reading a higher voltage when running, then yes replace the rectifier. The only two systems involved in charging are the stator and rectifier. When you bring your charged batter to your boat, bring some jumper cables. When you turn the key if nothing happens, leave the key on with the battery connected and jump the starter. If she turns over than you need a new starter solenoid. If she turns over but doesn't start check for spark in all 6 cylinders. start there and report back.

 

[kxracedad]

Re: 1984 Mercury 115 Generator

took the charged battery to the boat and it started, however i was not able to do any kind of tests. long story short, it lost both bumpers that were on it against a steel seawall and got some pretty bad damage. Then to add insult to injury a storm came up and I spent 20 minutes or better in the pouring rain holding it away from the seawall to prevent further damage. When it finally calmed down I was able to get it started and run it to the boat ramp to get it off the water.

now I have new problems

know anything about fiberglass repair and repainting metal flake?