i have a 25 hp yamaha 4 stroke that the crab was cloggeg no fuel out of the bowl . i took the carb off and cleaned a little fuel will come out now and will start for about 3 seconds and die. could it posibly be a fuel pump/ if so how do i check the pump. yes the motor has been sitting for 2 months
thanks

If you can keep it running by pumping the primer bulb after it starts, pretty good bet the fuel pump is weak.

Did you soak your carb overnight in carb cleaner? How old is it? Mght be a sticky needle valve needs replacing.

Sounds like the idle circuit, if it is carburated......not much you can do aside from some berryman's (parts house...follow instructions!) If it's fuel injected, I agree with fuel pump thing (check all filters first!)

Good Luck!

Do not forget the gas tank vent.

i tried to keep it running by pumping the bulb and it still died . going to get a carb kit abd going to soak it .
thanks again

Go buy a jet boat.

And stop trying to get up the River on Hubbard with your duck boat.

I can't beleive you sold your Skeeter during fishing season.

well i took it off and soaked it overnight put it all back on and still the same problem .
any more suggestions?

same thing, no start, or start and die after 3 seconds?

You have fuel in the carb bowl, but you sure it's not getting to the engine?

Have you tested for spark and compression?

carburetor float adjustment: holding carb upside down, the float should hang perfectly parallel with the carb body. adjust it by gently bending the float arm. [this is a generic procedure, I can't say for sure if your specific carb works this way but you should be able to tell]

if the carb bowl is full of fuel when it dies, then the pump isn't causing the problem.

Do you have a choke plate or a primer circuit? Is the throttle butterfly opening as it should? Have you checked the timing?

spray some carb cleaner (B-12) spray it in the carbs let it run for a while.
DO NOT SPRAY TO MUCH AT ONE TIME OR MOTOR WILL DIE.
I had a problem similar i sprayed B-12 and it never ran better.
my motor is a 2002 25 2 stroke yammy.

Don't spray that stuff through carb throats. It'll just go straight thru into the cylinders without touching the orfices or jets that you want to clean. Inside the cylinders it strips the lubricating oil from the cylinder walls. Every time you do that, you get a little closer to total meltdown.

If your problem is carbon build-up inside the engine, do a de-carb with Deep Creep (Seafoam in a spray can). Won't hurt your motor.

Do spray b-12 through all the carb orfices and jets. You can do that with the carb on the motor if your idle orfice plug is accessible. If there's an obstruction you might be able to clear it.

[quote=jtexas]Do spray b-12 through all the carb orfices and jets. You can do that with the carb on the motor if your idle orfice plug is accessible. If there's an obstruction you might be able to clear it. [/quote
I was told to spray B-12 into the carbs while the motor is running. my problem was that the motor would start fine but when we opened it wide open it only went about half speed. we took the boat home sprayed B-12 into the carbs while we hadthe rabbit ears hooked up. then the next time we took it out (about 1 week later) it ran better than it has ever ran. it is a 2002 yammy 2 stroke.
But what you said, we sprayed B-12 into the carbs,jets.

it finnaly started there was some real bad gas in the line . thanks for the replies