MERCURY 135 (1994) KEEPS DYING-HELP

[islander12]

I have a mercury 135 (94) that dies under throttle.<br />History: Accelerated to get boat on a plane, she cut out. tried re-starting, nothing. Eventually towed back to my slip.<br /><br />The starter motor turned over, appeared to be no spark.<br />I replaced the fuel filter, checked plugs, no carbonation, in fact all clean.<br /><br />Started motor, boom she fired. Wasn't happy as it sounded as if she wasn't firing on all cylinders (lay mans interpretation).<br />Had a friend of mine, who runs a marina check it out. He found some bad "grounds" cleaned them and ran the boat. Said it went fine and all was in order.<br /><br />I ran boat and under acceleration she cut out. Limped back to slip low revs, she cut out frequently. Pulled boat.<br /><br />Any ideas on where my problem might lie now? Appreciate any insights, before I go to the next phase.<br /><br />I plan to replace fuel line from tank to motor. Re grease the seal on fuel/water separator. Do i need to check carbs? I believe there are three as it is a six cyl. Can't believe that one would shut down the motor.

 

[KCLOST]

Re: MERCURY 135 (1994) KEEPS DYING-HELP

Switchboxes, stator, coils...?

 

[islander12]

Re: MERCURY 135 (1994) KEEPS DYING-HELP

KC,<br />You pose a couple of questions, since I am new at this could you be a little more explicit, please.

 

[dakk1]

Re: MERCURY 135 (1994) KEEPS DYING-HELP

Warren<br /><br />If it's fuel related, you could have a problem with bad gas, ventilation, restricted fuel lines, carbs and or fuel pump in need of rebuilding.<br />If it's ignition related you could have a bad stator,trigger,switchboxes,rectifier,idle stabilizer/spark advance module,coils or wiring connecting any or all of this.<br />Don't you just love outboard motors? LOL.<br />Easy things to check:<br />Spark gap test. See if your getting fire on all cylinders. Compression test. Give you a fair idea of mechanical condition. Squeeze the fuel bulb and or operate the choke while running. If you see a difference could be fuel related. Hope this helps.<br /><br />Dave..

 

[KCLOST]

Re: MERCURY 135 (1994) KEEPS DYING-HELP

Just like Dave mentioned...<br /><br />I recommend checking the spark an all the cylinders to determine if this is electrical or not...<br />THe fuel bulb trick is also a way to see if you have a fuel starvation issue...<br /><br />Spark gap tester is a cheap and effective means of checking spark, it's consistency and intensity... Auto parts stores carry them for around $10...<br /><br />What you find out on the spark test may point us in the right direction to diagnose the problem...