HP500's with carbs, one motor trips the 50A breaker during long (10-15 min) idle periods.

It only does this during the first putt out of the day, and after crusing and things are warned up, I can idle with no problems. If it trips, the fuel pump shuts off and motor eventually dies, but a simple reset gets me going again.

I've looked for the obvious loose wires and can't find anything. What's on the circuit controlled by this breaker? Probably the alt, fuel pump, what else? Has anyone experienced intermittent shorts in any of these components?

Anyone ever seen the breaker itself flake out with age? They've got about 100 hrs.

Thanks in advance,
Brian

Carb 500's don't have electric pumps did you add them?
The breaker has a red wire going to the starter motor battery connection. The other side (fused side) goes to all of the red with purple wires that feed the alternator, starter slave solenoid and the number 6 pin of your main harness this feeds the B connection on your ignition switch and any fused accessories up to a total of 40amps may also be hooked to this wire. Happy hunting I think the first place I would look is the electric fuel pump circuit if you have them. If you are hooked to the red purple side of the breaker and with them running cold (weak pump) it may be just enough to trip it.

I had that last year-- ended up the brand new alternator went bad --something came loose inside and would short when hitting waves.
Unhook the wires from your alternator and see if it still does it-- its gotta be something pretty big to pop that breaker --something else would glow cherry red with that many amps!

Use the process of elimination! Good Luck

Electric fuel pumps were added by previous owner. I agree with Mr. Sol, my problem has to be coming from something with a FAT red wire attached, as tripping a 50A breaker requires a pretty serious load. This has nothing to do with waves, as it happens idling thru no-wake zones.

It could be something with the alternator, but I checked the wires to see if there was something loose there - nothing.

My first shot will be changing out the breaker itself, in hopes that it's getting tired. It's only 25 bucks, and much cheaper (and easier) than digging into the alternator.

Thanks guys,
Brian

Just unhook the wires to the alternator first, and run the motor-- it'll only take 2 seconds to do and then you can rule it out. My guess is the breaker is working just fine and doing what it's supposed to do

Dave

Where is the electric fuel pump wired into? If its behind the breaker then maybe the pump and engine is drawing just enough amps to pop the breaker when cold........if thats the case try wireing the pump on a relay with its own volatge feed......may just be the ticket....if not..well i have no idea