volvo penta fuel or spark issue??????

[jodymartin]

Boat&motor- 1986 21' bayliner capri-aq225e #cu56837..... 305 with a quadrajet...

boat ran fine for the past 8 trips.... this last trip it ran good most of the day just fishing.. then i pulled the tube for about 5 minutes and it started acting up... sounded like it was starving for fuel so i got back to the dock with the throttle one postion it would speed up and slow down continuiously made it back and boat died and would not do anything... got it home and found a wire coroded into on the relay on the motor next to the ignition fuse on the motor.. fixed that and then it fired right up but still the same issue with it sounding like a fuel issue...... it was an old carb so i rebuilt it did the 24 hr soak and air pressure put it back on.. same issue for 20 or 30 min then all of a sudden it ran great rev up good and all for about 5 min then it died and now the same issue again????????????? i ran it out of a gas can to see if was a tank issue but same thing..... could it be the coil or batteries or points???? hope someone can help!!!

[captmello]

It sure sounds like a fuel issue...Do you have a fuel/water seperating filter? If not, I'd put one in. Re: points, I change mine every two years, some change them more. If you haven't done a full tune up in the last two years, it couldn't hurt and would eliminate those replacement parts from the list of possibilities. Set the points with a dwell meter.
305 tune up parts are cheap.

[jodymartin]

yes i have a fuel water sep. replaced whole dizzy, points, rotor, cap, plugs, wires all less than 6 months ago. and points are set with dwell meter.

i was thinking of running it out of a gas can to see if maybe the fuel has water?????

[jodymartin]

ok ran it out of a gas can with new gas for 30 min ...no change>>>> it will idle for a few minutes but if i give it throttle it make like a hissing sound and dies

[Mullin]

You could just pull a spark plug and check for water in the cylinder. Also, old oil filled ignition coils can act ok cold and bad when they warm up.

[jodymartin]

Boat&motor- 1986 21' bayliner capri-aq225e #cu56837..... 305 with a quadrajet...

boat ran fine for the past 8 trips.... this last trip it ran good most of the day just fishing.. then i pulled the tube for about 5 minutes and it started acting up... sounded like it was starving for fuel so i got back to the dock with the throttle one postion it would speed up and slow down continuiously made it back and boat died and would not do anything... got it home and found a wire coroded into on the relay on the motor next to the ignition fuse on the motor.. fixed that and then it fired right up but still the same issue with it sounding like a fuel issue...... it was an old carb so i rebuilt it did the 24 hr soak and air pressure put it back on.. same issue for 20 or 30 min then all of a sudden it ran great rev up good and all for about 5 min then it died and now the same issue again????????????? i ran it out of a gas can to see if was a tank issue but same thing..... could it be the coil or batteries or points???? hope someone can help!!!


i have a fuel water sep. replaced whole dizzy, points, rotor, cap, plugs, wires all less than 6 months ago. and points are set with dwell meter.

ran it out of a gas can with new gas for 30 min ...no change>>>> it will idle for a few minutes but if i give it throttle it make like a hissing sound and dies

[Bubba1235]

Boat&motor- 1986 21' bayliner capri-aq225e #cu56837..... 305 with a quadrajet...

boat ran fine for the past 8 trips.... this last trip it ran good most of the day just fishing.. then i pulled the tube for about 5 minutes and it started acting up... sounded like it was starving for fuel so i got back to the dock with the throttle one postion it would speed up and slow down continuiously made it back and boat died and would not do anything... got it home and found a wire coroded into on the relay on the motor next to the ignition fuse on the motor.. fixed that and then it fired right up but still the same issue with it sounding like a fuel issue...... it was an old carb so i rebuilt it did the 24 hr soak and air pressure put it back on.. same issue for 20 or 30 min then all of a sudden it ran great rev up good and all for about 5 min then it died and now the same issue again????????????? i ran it out of a gas can to see if was a tank issue but same thing..... could it be the coil or batteries or points???? hope someone can help!!!


i have a fuel water sep. replaced whole dizzy, points, rotor, cap, plugs, wires all less than 6 months ago. and points are set with dwell meter.

ran it out of a gas can with new gas for 30 min ...no change>>>> it will idle for a few minutes but if i give it throttle it make like a hissing sound and dies

Hmmm, a hissing sound screams vacumm leak to me.

[Don S]

Have you checked fuel pump pressure while running. Make a test hose between the fuel pump and carb, don't cut the metal line.
If the pressure is ok, you may just need a carb rebuild. Water and corrosion inside the carb is common in boats.

[jodymartin]

the previous owner already cut that line..... what should the pressure be??? The carb was just rebuilt...

[Don S]

I just merged your two posts together, please don't start different threads on the same subject. It helps to have all the information in one spot.

[Don S]

6-8 psi is spec for fuel pump pressure.

[jodymartin]

its 6psi

[Don S]

Time to go into the carb and have a look.

[jodymartin]

ok i put on a new carb and it runs better just not right....... at wot it surges up and down continuiously

[jodymartin]

gonna put a new dizzy cap, rotor, points and condenser to see what happens...... not sure what else to try

[Mullin]

Do boats have an EGR valve? (sorry I'm not all that familiar with boat setups, but if this was a car with a chevy 305, I'd say check the EGR valve and the idle air control valve.) If so, try plugging it and see if that fixes the surging.

[Don S]

Do boats have an EGR valve?

Nope, that's automotive, not marine.

ok i put on a new carb and it runs better just not right....... at wot it surges up and down continuiously

Why did you replace it? What what was wrong with the old one? Those are the kind of details that help find the underlying problem.

[jodymartin]

there was little pieces of the old hose in the carb filter so I figured some got through and clogged a jet or something. i think maybe the new carb needs adjustment but not sure how to do it

[jodymartin]

i also noticed that with the timing light hooked up the light blinks continious for a few seconds then stops for about a second then blinks again...... thought it might be the light???? but i put it on every plug and it acts the same except for the coil wire then it stays on..... could this be a firing issue????

[jodymartin]

well I guess no one else has any ideas time to spend the money and let a mechanic fis it