1984 3.0 Mercruiser quits suddenly.

[180American]

My 1984 Mercruiser 3.0 140 (1984 Wellcraft American)ran great for last 2 seasons until this year. First day out we went for about a half mile at 3/4 throttle and it quit right now. Almost felt like the engine locked up or vapor locked. It barely turned over at first and after 5 or 10 minutes it started ok. On the way back to the dock at around 2000 RPM it did it again. I've drained the fuel tank, it was clean, blew out the pick up tube, checked the anti siphon valve, replaced the fuel line, checked fuel pump for pressure and flow, rebuilt the carburator, installed new elctronic ignition, replaced the coil, spark plugs, set the timing, replaced all fuel filters. After all this it does the same thing. In fact, it will idle and run forever in neutral and up to 1500 RPM in forward gear, at 1800 rpm it quits abruptly every time. I can also run it in the driveway in or out of gear at any RPM with no problem. Anyone want to buy a boat?

 

[SpinnerBait_Nut]

Re: 1984 3.0 Mercruiser quits suddenly.

Welcome to iboats 180American.<br />Don't be to rough on the boat yet.<br />Let's get this over to the Merc/Volvo/OMC I/O forum for some help.

 

[captmel]

Re: 1984 3.0 Mercruiser quits suddenly.

My 1984 Mercruiser 3.0 140 (1984 Wellcraft American)ran great for last 2 seasons until this year. First day out we went for about a half mile at 3/4 throttle and it quit right now. Almost felt like the engine locked up or vapor locked. It barely turned over at first and after 5 or 10 minutes it started ok. On the way back to the dock at around 2000 RPM it did it again. I've drained the fuel tank, it was clean, blew out the pick up tube, checked the anti siphon valve, replaced the fuel line, checked fuel pump for pressure and flow, rebuilt the carburator, installed new elctronic ignition, replaced the coil, spark plugs, set the timing, replaced all fuel filters. After all this it does the same thing. In fact, it will idle and run forever in neutral and up to 1500 RPM in forward gear, at 1800 rpm it quits abruptly every time. I can also run it in the driveway in or out of gear at any RPM with no problem. Anyone want to buy a boat?

I am having the same problem, but mine are crusader engines, 1985. just wondering if there is a filter or screen on the pick up tube or a blocked fuel tank vent. if not you can try a new distributor. some one told me that can cause the same problem I think it is the mallory distributon has a secondary coil in the distributor. good luck