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Chokes out under a load

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Mattturner

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2008 Crownline 21SS with 350 efi bravo 3. Engine starts and runs fine. Sounds good. When I give it throttle to get out of the hole, it may take off briefly but then acts like its starved for fuel. Engine doesn't die but sputters and has no power.*

Prob orig began when I was making some hard turns left and right. As I would come out of the turn, the boat would have no power. I'd throttle back to neutral and then go just fine. As it got worse, i could get out of the hole fine and then it would choke out. As I give it throttle, it sputters and sounds bad. When I pull throttle back to idle, it runs fine. I am great in a no wake zone! *

I replaced the cartridge style fuel filter and the boat ran last night. It didn't get to top speed and it felt like it was lacking performance but it ran. Then as I was clear across the lake, probs began again. At 50 mph and 4500 rpm, it hickupped. Then again. I throttled back and was able to run about 3000 rpm back to the dock. Any help is appreciated. Thank you.*
 
It may be as simple as checking all of the spark plug wires...one or more may be loose or failing. When were the plugs last changed?
 
Just had the plugs changed when it was winterized in October, 2011. I'm sure new plug wires weren't installed then. How would I know if that's the issue? What else could it be?
 
You are looking for a loose plug wire...squeeze and push the wire on tight because they can vibrate loose.
 
I'll check plug wires ASAP. Someone also said I should see if one has a burned or worn spot. I'll also put in some Heet but I'm doubtful because it started to have this issue before I filled up and now is continuing after adding 30 gallons. But I'm going to try. Any more ideas? I'll update as soon as I've done these things.
 
I pumped all the fuel out of my onboard fuel tank when i got it.

You can do one of 2 things, pump the water out of the bottom, or all the fuel out and here is how.

If you just wish to pump just the water out of the bottom of the fuel, you will need to purchase a cheap electric fuel pump from any auto store dc powered.
You will also need about 15 foot of cheap fuel hose from the auto store and clamps to fit the fuel pump.

Install the hose on the fuel pump both ends and cut about five feet on the sucking side of the pump just look for the arrow on the pump.

Remove the fuel pickup tube it's the one where the fuel hose hooks to the tank a 90 degree angel fitting, it's a anti-siphon valve. Unscrew it.

Crank the bow of the boat all the way up, and stick the hose connected to the electric fuel pump 5 feet into the bottom and back of the tank.

Into a clear container pump the water out till you see clean fresh fuel and stop the pump.

Or into a large container pump all the fuel out.

Now check the valve by blowing thru it, check the screen thats its clear.

Install the valve and pickup tube your done.

Question do you have a fuel water separator on the boat, good to have.

Good luck !
​
 
Ok. I can do all of that. I'll try pressing on the plugs, checking the plug wires and draining the bottom of the tank tonight. Would adding a couple of bottles of Heet be ok instead of pumping the fuel tank or not?
 
Ayuh,.... 'n check the distributer cap, for Cracks....

just ran across this same thing,... sorted out the fuel system, 'n was lead to the cracked cap...
 
Distributor cap cracks will be obvious??? Will a crack be a CRACK-Crack or could they be small hairline lil things that I won't be able to tell without a keen 6th sense and a microscope?
 
Mattturner said:
Distributor cap cracks will be obvious??? Will a crack be a CRACK-Crack or could they be small hairline lil things that I won't be able to tell without a keen 6th sense and a microscope?
Click to expand...

Ayuh,.... could be either, or both.... look for carbon tracking....
 
Just had the same symptoms with my 7.4. Turned out to be a bad pick up coil. The timing wasn't advancing far enough to get past 3200 rpm. A bad plug wire could do the same thing too. The module could affect it too.
 
Sure sounds like a fuel problem. Temporarily substitue a 6 Gallon auxiliary tank from an outboard motor to see if the problem disappears.
 
Turned out that the prob was the engine was in Protection Mode or something like that. It was low on oil and it protects itself from damage. So how's it low on oil? I don't see any in the boat. Guess its burning it. Ugh. How bad is that?
 
that's called Guardian Mode....the computer is trying to protect the engine from the operator.

Your horn should have been beeping...if you didn't hear it, it may be disconnected or inoperative - may wanna get it working
 
Mattturner said:
Turned out that the prob was the engine was in Protection Mode or something like that. It was low on oil and it protects itself from damage. So how's it low on oil? I don't see any in the boat. Guess its burning it. Ugh. How bad is that?
Click to expand...

Ayuh,.... My guess is, that motor's got an oil cooler, 'n it's internally split from a bad winterization....

Oil pressure is higher than the water pressure,... yer pumpin' yer oil, Overboard...

Btw,.... Don't you Check yer oil, at the beginin' of every outing,..??
 
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