View Full Version : Why does my engine stop on its own?

06-22-2008, 05:41 PM

I'm having a problem that even the mechanic I sent the boat to is not sure what causes it. I have a 2004 Mobius with the carburator motor.

The engine starts normally, runs for about 3 to 5 minutes then shuts itself off. I can start the engine immediately after with no problems, but then it shuts itself off again.

The boat ran perfectly last season and only began doing this when I took it out of winter storage this year. The only difference since last year is that I got new spark plugs and a new impeller.

I can't figure out what's going on, any guess would be welcome. My guess is a fuel filter, but the mechanic is unsure.


06-22-2008, 07:15 PM
Here is a question for you. When the boat was winterized, did you put stabil in the gas? Second question. Did you use the anifog in the carberator? If so, I would have them check the Carberator. The old gas could have turn into varnish and is clogging the fuel intake.

06-22-2008, 08:56 PM
I'd start with filter, then check fuel pump... definetly sounds like loss of fuel pressure. let us know...

06-23-2008, 09:43 PM
I would agree that this is a fuel problem. Sounds like the boat starts and empties the fuel in the float bowls and then starves for fuel and shuts down. Probably before you actually turn the key to "Start" when in the "Run" position the pump moves enough fuel to fill the bowls, but just can not keep up. Start with the fuel filter.

Here is another test to test for fuel. When the boat shuts off, immediately remove the flame arrestor and have someone "floor or pin" the throttle and see of any gas gets injected into the carb.

My dad which is much braver than me, takes a turkey baster and sees how long he can keep it running by dripping the gas into the carb directly, this is also a good test for fuel, but dangerous!! It will definately tell you if it is fuel related, but again VERY dangerous. I always get dad to do this test for me. I am chicken...

07-03-2008, 10:25 PM
FIXED! Mechanic changed a fuel pump relay and voilą!

07-03-2008, 10:42 PM
THANK YOU for following up. This is always very helpful!!!