1985 Mercruiser 260 Sterndrive ran out of gas cuts out and dies and wont start

[DirtyMaxin]

Recent purchase, 1985 Cheyenne Mini Day Cruiser Mercruiser 260 Sterndrive. Boat runs great on the trailer, itll hold 3k and wont miss a beat.

The first trip out, realized my selector switch for my fuel tanks was going out (found out by running it out of gas). Got towed in, took it home, replaced the toggle switch, pulled fuel filter and filled with fresh gas, lubed seal put it back on, still wouldn't start. Tank selector valve was loose and rather than try and repair it, I picked up a replacement, and she fired up after that and has continued to fire no problem, on the trailer. Took it out yesterday to make sure it was all good before we go camping tonight, fired right up, boat got on plane no problem, she cruised nice. As we came away from the marina I opened her up, and at 2900RPM she cut out, as if the key were shut off. No stumble, no loss of power, just dead. She would crank but wouldn't start. Pulled spark arrestor off and checked carb, had fuel. After about 20 minutes of moving the choke open and closed, I tried her and she fired right up like nothing was wrong and she stayed running. We decided to move on and see if it happened again. I ran it at 2200RPM for a good hour and she never missed a beat. Then we hit the main body of the lake and I pushed it. We got to about 2600 RPM and out of no where, cut out again, wouldn't start.

I'm going to my boat shop today for a new fuel filter/water separator, but what else should I be replacing? I've read that similar things happened with bad anti siphon valves, but that it should still start after, also read about an actuator arm in the distributor? Also read it could be a bad coil, The first time, I had my friend holding the spark arrestor while I start it to check for fuel in the carb and it arced on the coil body before I even turned the key, is that a sign of a coil problem?

I need some advice quick, supposed to leave tonight at 6 pm for camping!

Thanks guys!

 

[alldodge]

Pulled spark arrestor off and checked carb, had fuel

holding the spark arrestor while I start it to check for fuel in the carb and it arced on the coil body before I even turned the key

You have fuel so that shouldn't be the issue. You got a spark from the coil without the key ON?

My first guess is your loosing power to the distributer. Next time it dies, need to check for 12V on the POS side of the coil, and for spark

 

[Scott Danforth]

did you replace the points? have you checked the dwell and timing?

do your gauges remain powered up, or do those die as well? if the gauges die, your loosing voltage at the key switch, or before.

it sounds like an ignition component on the way out, or a bad connection on the ignition supply wire like AllDodge indicated. (working backwards, coil connection, main harness connection, main harness extension connection, main harness dash connection, safety lanyard, ignition switch, then back thru main harness connections on the 12 v supply wire)