Mechanic Help?

Hey guys, have a stalled boat after a morning session. Thinking maybe fuel filter? Any other ideas?

Check the kill switch lanyard.

Start with fuel and spark checks. Does it have both?

Cut off was the first thing checked. All plug wires are secure and the gauge read 1/2 tank and added 5 gallons anyway. Boarder went down and as I circled back around it cut out on me. It turns over just won't start.

Yes but you have to actualy verify spark and fuel are actualy making it to the engine. What type of boat and what engine?

08 Moomba Outback V 325 motor. Throtle body is not moving when throtle is engaged. Is that normal? I thought it would move. Seems as though it can't decide between in gear and neutral.

The throttle body plate doesent move? Did you take off the spark arrestor to verify the throttle plate isnt moving with the throttle?

I'm not familiar with the specifics of the 325 in the '08 Outback but I'd guess based on the year that it's Throttle By Wire meaning that the cable coming from the throttle lever just moves a little sensor and is in no way directly connected to the throttle body. The computer monitors this signal and moves a stepping motor to open and close the throttle body as it sees fit. So, it wouldn't surprise me if the computer keeps the throttle body closed until the engine starts.

As stated before check spark. Remove a sparkplug, reattach the boot and ground out the tip of the sparkplug somewhere on a bare spot on the block or somewhere that you can get a good ground. Have a helper crank it over and watch the gap on the plug for a spark. Only hold the plug by the rubber boot unless you want a little bit of a shock. Alternatively you can get a little spark tester at any autoparts store. This is a little bit safer way to do it because it just plugs inline with the sparkplug and theres a little plastic/glass tube that you can observe the spark through.

If no spark then you've got some sort of ignition/ECU/kill switch/misc. electrical issue. I doubt that boat has a distributor cap being an '08 but if it does pull it off, look for moisture, make sure the little spring loaded contactor in the top of the cap is clean and moves freely. Make sure the rotor's tip isn't fouled with carbon buildup and the little tab in the middle that contacts the cap is clean.

If you have spark then you need to check fuel. The first thing to check would be that you hear the pump priming when you turn the key to the on position. Be quiet and listen for it. If you don't hear it remove the access panel to your pump and try again. If you still don't hear it have a helper do it while you put your ear by the pump. If you still don't hear it your pump is likely bad. For further diagnosis you can get a gauge for around $30 or so that screws onto the schrader valve on the fuel rail. You'd have to research what your fuel pressure should be for that boat.

If no or low pressure then you likely have an in tank pump with a large screen type filter on the bottom but someone more familiar with your specific boat will be able to tell you more definitively. Pull the pump/filter/pickup assembly out and checkout the filter. It would have to be pretty junked up to cause the boat not to run at all so I'd be surprised if the filter is the problem so you're likely looking at a pump replacement. Not sure about your boat but generally you can find suitable replacement pumps at a regular auto parts store. Moomba likely just sells the entire assembly for several hundred dollars. You may be able to find the bare pump that can be installed into that assembly for around $50 or so at a place like NAPA.

Check fuse (which may be in line) for the fuel pump as well.

A friend of mine did this on a Merc I/O a few years back and there was a fuse down on the starter that he cooked. Seems like it was a $15 part....might check that to.