Mercruiser 5.7 (2003 Carburated) Suddenly Won't Start

[Scorpion8]

Came in from cruising 10 days ago. We have a rather lengthly harbor approach so the engine wasn't run high and then just flipped off, it had lots of time to come down to stable temps. Shut her down like normal and closed the boat (2003 Trophy 2359) up. Went back last night just to run the engine, charge the batteries (bilge pumps runs a lot right now due to rain) and she wouldn't start. Barely even coughed a couple times. I wasn't dressed for crawling around on hands and knees with wrenches but.... thoughts?

Didn't seem like loose battery cables, as it turned over fine. There's 20+ gallons of fuel in the tank, but fuel filter? Fuel pump? Ideas of what to look for first?

 

[alldodge]

I would start with seeing if gas is present in the carb. Look for fuel going in as throttle is moved, then check for spark

 

[Scott Danforth]

here is where I like to use WD40. you stated is raining. if there is lots of moisture and your plug wires are marginal, you could be cross-talking or simply the spark is taking the shortest path to ground.

hose down the plug wires with WD40 and try it. you may also have to pull the cap and dry it out as well.

 

[NHGuy]

Also make sure you haven't knocked loose the emergency kill lanyard.

 

[Scorpion8]

Also make sure you haven't knocked loose the emergency kill lanyard.

That is a suspect area that I was looking at on the throttle control.

 

[Scorpion8]

Went down to the boat last night and sure enough the kill switch lanyard and safety clip is gone. Looks like somebody wrenched on the kill-switch with a screwdriver too, as it flops around about 1/2" without fully coming out. Odd, because the boat is locked by Trophy/Bayliner windows aren't the most secure. A universal kill-switch lanyard with the 8+/- different clips didn't seem to have one that fit. Is it the loop-type retainer or another special Trophy-only part? Anybody know the Trophy part number? Part # 1754392 (replaces 1703502) gets you the whole throttle assembly, but I can't find a part # for "just" the kill-switch.

 

[alldodge]

You sure one of the universal ones won't fit?

 

[Bondo]

Ayuh,.... Jumper the wires, 'n by-pass it,....

 

[Scorpion8]

Turns out it was the rotor in the distributor cap going bad. The engine kill-switch was bypassed some time in the past by the previous owner, and must have been dislodged from it's spot. It looks like it had been wrenched on because, well, it had at some point by an unskilled hack. Distributor was fixed up and she starts like a Swiss watch again.