3.0L Merc won't start

[mikeinsac2003]

I have a '92 Bayliner with a 3.0L Mercruiser. Bought it a year ago and never had a problem with it. It has sat for a couple of months, but has been ran since winter(when it sat for 7 months).<br /><br />Tried to start it this weekend, but it wouldn't. At first, the engine would just very slowly turn, with a slight buzzing sound(sounded electrical). Then after a few attempts, it would not turn at all. Figured it was the batteries(2 Heavy Duty). Was able to position the boat so I could get a jump from someone onshore. Was able to connect to someone with a Ram 2500 who also had two batteries. Engine would turn maybe once or twice and then "struggle" to turn at all. After 1/2 hour, we were both out of patience and called it a day. Pulled the boat out and left in the parking lot over night. Next morning, I wanted to start with a fresh battery so I pulled the Heavy Duty battery out of my 4Runner and tried to start it while still on the trailer. Although the engine was really struggling to turn, it did start after several attempts.<br /><br />Convinced now that my batteries must have just been drained, I put the batter back in the 4Runner, put the boat in the water, pulled the 4Runner battery again and connected it to the boat. Several "struggling" tries later, it fired up. I disconnected the 4Runner battery and reconnected the boats batteries.<br /><br />I then proceeded to drive around the lake for about 1 1/2 hours trying to charge the batteries. Volt meters registered great and all seemed to be working. Pulled back into shore and turned off motor. Tried to restart and I got nothing but a low buzzing noise. Not even a "struggling" turn of the engine. Brought back the 4Runner battery which had been recharged by my wife while I was out, but this time not even the 4Runner battery would turn the engine. After several attempts, I could smell something electrical burning. I looked back and saw a bit of smoke coming out of the starter area. Figured I might have overheated it....waited 1/2 hour and tried again, but still nothing.<br /><br />Thought I would ask for advice before I just started taking things apart.<br /><br />I would have thought it was the batteries except for a couple of things:<br /><br />-Never once had a problem with them yet<br />-Would have thought the jump from the Ram 2500 w/two batteries would have turned it over<br />-Volt meter shows everything as juice<br /><br />Can it be the starter? Does a starter go bad and just not have the power to turn the engine anymore? It seemed like it was really struggling. Almost like the engine itself was really hard to turn. However, I was able to get it started and run for 1 1/2 hours.<br /><br />Sorry for the long post, just wanted to give as many facts as possible to aid in any diagnosis.<br /><br />Thanks in advance for your help.

 

[SpinnerBait_Nut]

Re: 3.0L Merc won't start

Don't know how the start system is set up, but what you described sounds like a dragging starter.<br /><br />And after the engine gets warm it is that much harder to start, hence your problem after running it.<br /><br />The buzzing noise you are hearing is your starter relay.<br /><br />It will sound the same way when battery/s are dead in a car.<br /><br />If you can jump engine at get it started, then this will almost rule out starter relay and point to the starter as your problem.<br />Might be a ground also.<br /><br />Check all the wiring to starter and pay close attention to ground connections for any corrosion, or looseness.<br /><br />Hope this helps.

 

[JB]

Re: 3.0L Merc won't start

Moving to I/O