Mercruiser 470 Stalling

[kyddvicous13]

Okay guys back again, I was out running my boat last night, had a 15 mile run to get to where we were planning to fish for the night. Boat started fine, idled fine, and ran good for about 7 miles. While up on plane at 3k rpm it just sputtered for a second then died. I was having an issue with it flooding and replaced the carb so that was my first check. Wasnt flooding, getting volts everywhere I should have been. Temp gauge wasn't reading hot. Getting fuel to the carb, just wouldnt start back up. After sitting about 20 minutes it starts back up after about 3 miles the same thing. Not sure where to even start, the engine seemed hot I know not to trust a gauge but I didnt have a way of checking the actual temp out there. I only seem to have the issue under load in the water. Would the engine stall if it starts to overheat? All the ignition components, alternator, batteries, and impeller were replaced. Seems to have good water flow while running on muffs. Any help would be much appreciated!
80 mercruiser 470, 190hp w/ MC1 drive

 

[stonyloam]

Re: Mercruiser 470 Stalling

My first guess would be an electrical problem. Did you check to see if it had spark just after it stalled?

 

[Propeye]

Re: Mercruiser 470 Stalling

How did you set the point gap, and did you reset the timing advance after replacing/adjusting the points?

 

[kyddvicous13]

Re: Mercruiser 470 Stalling

It had spark, and it has an petronix electronic ignition unit in it.

 

[a1nowell]

Re: Mercruiser 470 Stalling

kyd13,
Check out my thread from April, I bet it's your coil.

http://forums.iboats.com/showthread.php?t=541400&highlight=a1nowell

Larry

 

[stonyloam]

Re: Mercruiser 470 Stalling

If it has spark, could be a fuel issue like a plugged vent not allowing fuel to flow to the pump. Happened on my combine, loosened the cap, cleaned the vent and worked fine after that.

 

[kyddvicous13]

Re: Mercruiser 470 Stalling

The vent doesn't seem to be clogged. There was no air flow when I removed the cap, and you can smell fuel from it. I have a 10 horse kicker that is run off of the same fuel. I didn't have the valve closed to the outboard while running the main motor, could this cause the system to suck air into the fuel lines?

 

[squarehead]

Re: Mercruiser 470 Stalling

still got problems ? sounds like hot carb to me. the gas is boiling and air replaces the gas in venturi. cools down and runs again, probably started hard when it's up to temp. try running a fresh air hose as close to carb as possible to cool it down. check oil level, it should be growing slightly and smell like gas as a perking carb will flood the engine when it's shut down, thats why it starts hard