Laboring getting on plane

CoachDePo2

Cadet
Joined
Oct 16, 2016
Messages
7
I have a 1991 222 Cobalt Conduere with a Bravo 7.4L V8 engine. The boat starts right up and idles fine. When I start to go fast it labors getting on plane. Almost like it’s laboring to get up out of the water. It is like a rough start. Once I get going it goes fine but doesn’t seem like it is going full power. I have it full throttle and it goes about 40+. I am removing all the fuel and adding Seafoam and all’s my try dry gas. Not sure if it is bad fuel or possible weak fuel pump. Any help or suggestions is greatly appreciated!
 

tpenfield

Moderator
Staff member
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Jul 18, 2011
Messages
18,523
What is the history of the boat as far as you know? Did it at one time come out of the water more quickly?

Check engine compression. See if you can find if the boat is retaining water anywhere.
 

CoachDePo2

Cadet
Joined
Oct 16, 2016
Messages
7
I have had the boat for 6 years and it was fine until recently. I had it services and they cleaned the carb and fuel filter and replaced the coil wire. It ran fine at 1st then started again. It is not a very significant change but I can’t tell it’s not going getting as much power as it previously had. Thank you for taking the time to respond.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
Messages
51,478
Check compression

Make sure accelerator pump in carb works
 

Old Ironmaker

Captain
Joined
Dec 28, 2015
Messages
3,050
I am going to guess you may have weight below the floor. Buddy had the exact same symptoms on his early 90's StarCraft 19 footer 150 HP Johnson. We went through everything mechanical and fuel related, unfortunately it developed a leak sometime last fall. He didn't notice anything as the boat was slipped and the bilge was dry. A dead battery was a warning as well as the scum line is now higher than normal. Hope yours isn't that.
 

CoachDePo2

Cadet
Joined
Oct 16, 2016
Messages
7
Well got it taken care of. Distributor cap and wiring went bad, had plugs replaced and carb rebuilt. Picking it up tomorrow to test drive it hopefully that was the problem. I changed the filters and replaced the coil wire as well. Heading for a weekend boat trip. Anxious to test drive it. I was told it was water tested already. Thank you all for your input much appreciated.
 
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