Mercruiser 3.0 won't start

r_snowrider

Seaman Apprentice
Joined
Jul 9, 2005
Messages
38
Howdy everyone. This is my first post. I have some questions about a Marlin with a 3.0L 4 cyl merc engine. I'm not sure what year it is.<br />The problem started last year. Our boat would run well for the first little while, then it would putter out and die after a little while, but then it would start right back up again just fine. It would continue to do this throughout the day whenever I accelerated hard. Well we just kinda lived with the problem. Well I pulled out the boat this year and now it won't even start, the started engages but it won't turn over. I checked the fuel pump and it's working. Then I checked for a spark and got nothing, definately a problem. I don't know what could cause this. But if any of you fellas could give me some tips on some things I could try before I try to replace something that would be great. Also, do you think that last years problem could have a link to the problem I'm having now? Thanks for your help. Ryan
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: Mercruiser 3.0 won't start

tough to say exactly with out a year but its sounds like its in need of a good basic tuneup with all new parts <br /><br />it sounds like the motor is turning over but not starting ? is this correct<br /><br />cap,rotor,fuel filters,points if you have them all these parts are once a year items to keep the motor running correctly <br /><br />it really doesent matter how much you use it water takes its toll<br /><br />after that see what happens with good spark and you can take the next step
 

Marlin1

Cadet
Joined
May 24, 2005
Messages
26
Re: Mercruiser 3.0 won't start

Try checking the coil or maybe the points.This would be A good place to start looking.<br />I also have A Marlin with A 3.0<br />great little boats...
 

r_snowrider

Seaman Apprentice
Joined
Jul 9, 2005
Messages
38
Re: Mercruiser 3.0 won't start

Thanks a lot guys. The first thing I probably need to do is clean the points. Problem is I am not very knowledgable about the ignition system. Where exactly are the points, and what should I use to clean them?
 

chrisg

Chief Petty Officer
Joined
Jun 29, 2004
Messages
476
Re: Mercruiser 3.0 won't start

I also have a merc 3L I/O and had the same issue, when I whent to start it, it turned over,but would not start. Took the plugs out and found no spark. <br /><br />Cawled all over the engine, looking for the problem. Called up several marinas to see if I could get in. All were busy, but one told me to check the energency shut off switch up by the drivers seat.<br /><br />Sure enough, the switch was not fully on!<br /><br />If you have a switch like that, toggle it off and on a few times.<br /><br />Good luck!
 

r_snowrider

Seaman Apprentice
Joined
Jul 9, 2005
Messages
38
Re: Mercruiser 3.0 won't start

Thanks for the info fellas. I have narrowed it down to a bad coil. I'm not getting any power to the plugs. So I checked the points in the distributor, they looked fine. So then I moved on to see if I was getting power out of the coil (using the shock therapy method), again no spark. So I checked to see if the wires connected to the + side of the coil were getting power, I got a reading of a little over 12v, so they were working. I don't have a safety kill switch, atleast I can't find it anywhere. So I guess it would be a bad coil. Gonna go get one tomorrow. I'll let you know if it works.
 
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