bbc loses voltage

[euro scott]

need suggestions, i was running the big cat yesterday and ran about 80 miles and was running great as i came into a no-wake zone idled down and had run about 2-3 minutes at idle, one motor just shut off, like a kill switch was pulled, the tach and guages still at the levels they were at when running.i swung the boat around to head out in the open water so to check it out, and after about 10 minutes i noticed i had the key on for that motor and the guages went to 0 and i pushed the starter and it fired right up,did this same sequence 2 more times before i got to the ramp, it seems something gets hot and opens up,at first i thought an msd box going bad but that doesnt make sense, maybe a starter silonoid shorting out? the motors are 540's, carbed, with not a lot of electrical crap one year old and no corrosion.. the biggest problem is testing as it only does it when hot .
thanks
scott

[vector mike]

Sounds like it could be a coil issue. I have seen them shut off when hot and start right back up when they cool down. I also had an ignition box do the same thing.

[Bartman39]

Is the tach signal coming from the MSD box...? If so and it keeps it at the RPM it was running at then it points to the box itself and yes they do go bad... Thats why in Nascar they run 2 boxes for the system so they can switch in the event of a failure... Just because it has no moving parts does not mean it wont fail... Sorry just a fact...

[The Big Al]

I would expect this is a Mercruiser?

They have a master circuit breaker. When hot will trip and when cool reset.

The MSD box will work on not work.

Intermediate operation is rare! Very Rare! When it fails it's dead!

(and the NASCAR boxes are very different than the consumer)

I assume your running a 6 MSD ? and Not the 7 MSD.

The 7 MSD will get hot and reset! It's not recommended for long term use.

Al

[BUSHWACKER]

Check the tightness of the screws for the wires on your ignition switches.

[euro scott]

last night i checked the key switch, the purple wire leads on the back of the helm , the coil wires and other grounds and wires around the ignition, nothing detected. ran the motor for 1/2 hour to try to get it hot and never acted up, looks like i have to go back to the water with test light.
i think i'll switch coils to other one as i have the msd 6 box, and maybe it will follow.. the bummer of it is its on the motor that runs steering

[CAPTAIN CAMPER]

It sounds like you have a power problem if you shut the other motor off all the gauges will stay where they were if they do you are losing power possibly master thermo switch see if you still have power to ignitin switch when motor shuts off

[euro scott]

no power at the switch or starter button

[THE HOGG]

JUST BRING IT TO JACKSONVILLE, ME AND RACEMORE WILL RUN THE PI$$ OUT OF IT AND FIND THE PROBLEM FOR YOU:eek: OR ATLEAST BREAK SOMETHING ELSE..

[Greg Moss]

Check the fuse on the starter. It looks like the same thing as they use on the trim pumps. All your power comes through it at the starter battery lug. The power for all your electrical come from there it is square and the 1/4" nut on it will work loose sometimes and will loose connection. some reason those things get hot and the bolt or fuse what ever is in side it stretches. That is what I would check first.

[euro scott]

thanks greg, i will check it better tonight, only problem is i have to be a contortionist to get to it...
hogg, you got some good water to break some parts in up there?

[bmax]

Since you lost power to the ignition , and then lost power to the guages , i would be looking at the source . Check the harness (plug) at the motor . This is the source to the dash , and then back to the motor . Assuming all batt leads , solenoids , alt connections are good .

Good luck !

[THE HOGG]

thanks greg, i will check it better tonight, only problem is i have to be a contortionist to get to it...
hogg, you got some good water to break some parts in up there?

I GUESS, IT SEEMS TO WORK GOOD ON MY STUFF:D

[Wile E. Coyote]

if its twins, just start switching suspect parts one at a time from the problem motor to the good motor, you'll find it soon enough.....:D

[euro scott]

it seems that the replies about the starter solenoid , nailed it... i finally found it at the starter, it was the lead from the motor to the soleoid, the one i never touched , the lead that comes on the starter that you never hook a wire too thats from the factory was loose and causing intermittant loss of power..
thanks All
scott.

[THE HOGG]

Now Bring It Up And Lets Take It For A Test Romp:d