Engine Issue

[rudyfigueroa]

Need some advice, I have a 2005 Advantage Jet Boat with a Indmar big block Chevy 502 carbureted engine. I have stalling issues, I’ve emptied the gas tanks and all clean, changed fuel pump, alternator, new carburetor and I can start it with the turn of the key not pumping gas pedal and it idles but soon as I push on the gas peddle and put a load on the engine it will rev up nicely for 15-20 secs then dies. Some say the coil may be the problem? Any ideas out there??

 

[Maestro]

Does it start right back up?

 

[rudyfigueroa]

Does it start right back up?

Yes it does..

 

[mash on it]

Holley carb? Check the float levels.
Needle and seat can be an issue too.

Dan'l

 

[rudyfigueroa]

Yes it does..

Yes it does..

Wish I could upload a video of it in action on the launch ramp. It shows it starting up easily with turn of the key and idling slowly but running, then second I push on gas pedal it sounds strong and I can rev the engine and see the water exiting the basset headers then the engine shuts down. Prior to replacing all the parts I had the same issue..

 

[Riverbottom]

Water injected Basset headers ? How is the water controlled to them at idle ?

 

[BajaMike]

Vacuum leak?

 

[obnoxious001]

Wish I could upload a video of it in action on the launch ramp. It shows it starting up easily with turn of the key and idling slowly but running, then second I push on gas pedal it sounds strong and I can rev the engine and see the water exiting the basset headers then the engine shuts down. Prior to replacing all the parts I had the same issue..

You made no mention of fuel filter, what do you have?

 

[Teague_JR]

Stuck anti siphon valve at the fuel tank pickup? blocked/kinked fuel tank vent?

 

[74 spectra20 v-drive]

I am with Barry, fuel filter, collapsing fuel line especially with the fuel we have now.

 

[Streetmoto]

I agree, sounds like a fuel flow issue. If it were me I'd try filling the float bowls on the carb, disconnect the fuel lines into the carb, start the boat and give it a quick rev before the float bowls empty to see how much fuel is pumping through your lines. Obviously take caution with the fuel so nothing catches fire, maybe fab up an extension to the fuel lines so it feeds into a bucket outside of the boat. Since you replaced the pump it's probably an issue with the filter, lines or tank pickups. I'm guessing the same issue happens regardless of what tank you're using? If so, you can probably take the pickup out of the equation (highly unlikely both tank pickups failed at the same time) which leaves the lines or fuel filter. How about the fuel selector, is there any way that could have been damaged creating an air (vacuum) leak? Should be easy to bypass the fuel selector to take that off the list.

If the fuel flow is solid, the only other thing it could be is ignition. Might be worth trying a different coil/replacing your spark plugs and wires etc. Good luck!

 

[farmo83]

I agree check the lines.

I spent months and tons of money chasing down what ended up being a stuck piece of wood in the brass T tying the tanks together. How it got there I couldn't say.

 

[guest hs]

Take a 6 gallon outboard tank and hook it to the fuel pump and eliminate your entire fuel system from the boat, make sure you vent the outboard fuel tank