Boat scared of the water!! 1976 55hp

Hello everyone, I'm new to this site and really need some help with my boat. I have a 1976 Johnson 55 hp Seahorse. It will run all day long on land with the muffs and water of course, but when you put it in the lake, it will only start for about a minute, then die and will not start again. I'm lost for causes. Its got a new ignition switch, carbs rebuilt, new starter, new plugs gapped at .040, new power pack, new batteries. The choke silonoid readjusted to 3/16" and floats adjusted to 1/16". Fuel filiter cleaned, with new fuel with a mixture of 20 ounces per 6 gallons. Any help will be greatly appreciated. I've never seen a boat that will run on land and not in the water!! Now this is hilarious!

Re: Boat scared of the water!!

those,..are a well documented prob w/the labyrinth seal,on crankcase halves.,....however,...try,to just idle it up,......

Re: Boat scared of the water!!

Thanks for the answer. I brought the boat home, and it started right up, without a hitch. Mind boggling, I assure you. The motor didn't stop till I turned it off.

Re: Boat scared of the water!!

my suggestion----to all the 50--55 2 cyl boys,...seriously,..is get a 3 cyl 70--74 or ltr....now that...is an eng...i have built MANY.....lovem

Re: Boat scared of the water!!

Start with a new 6 gallon fuel tank, new fuel line and bulb, and fresh fuel. See if it will run on the lake on that. I had one with really odd issues like yours. Turned out to be a detatched fuel pick-up in the tank. At certain angles, it got fuel and ran. At others it would not.

Re: Boat scared of the water!!

This is a very odd post. I have been thinking about it and I can't make any sence of it. I would back the boat just far enough in the water to cover the water intake holes. Then see if it will run for a prolonged period of time. If it does, then the problem must lie with water getting into the motor or something of that nature. I wish I was there to help, I love a good riddle.

Re: Boat scared of the water!!

What is your idle set at?
Those engines will run great on muffs with a low idle, but when put in the water, the backpressure will stall the engine if the idle is to low.
The idle should be about 650-700 in gear in the water.