Engine ran great for 20 minutes then lost ALL power, only idles...

I just bought a 2005 Johnson 6hp outboard. Motor ran fantastic on trial run. When I bought it home it ran fantastic for about 30 minutes, then it gradually started to lose power over 2 minutes until it literally had NO power and just idled. The engine revs when I crank it up but doesn't move the boat at all. The engine then stalled. I tried to start it up again, but to no avail. After rowing with oars for about 5 mintues, it started back up again, but still had zero power.

After speaking to a friend, I suspected it was the fuel line bulb, since it was literally rock hard at all times, even when disconnected and when the engine is running. But I got a brand new fuel line assembly and then tried starting it in a bucket of water. Started up right away, but still didn't rev up a lot, plus it stalled again within 2 minutes.

Any input?

Model # is required here.-----2 stroke ?----Are you mixing gas and oil properly ?----------4 stroke , have you checked oil ?--------Have you checked operation of waterpump ?

racerone said:

Model # is required here.-----2 stroke ?----Are you mixing gas and oil properly ?----------4 stroke , have you checked oil ?--------Have you checked operation of waterpump ?

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Johnson J6RS0. It's 2 stroke. Got the correct oil and used correct ratio of 50:1. So 8 oz per 3 gallons.

So far I've replaced the fuel line from tank to motor. What's strange is the previous primer bulb was rock hard at all times. Now the new bulb pumps easily but NEVER gets hard. Plus I don't hear any swishing of gas like you'd expect. Is it supposed to be audible and can you feel it go thru bulb?

What stumps me is how engine ran great for 30 minutes! If it were the external fuel line from tank to motor, wouldn't it have crapped out long before 30 minutes?

The bulb is nothing but a " manual pump " and you should get the sensation that you are pumping fuel.---------After you fill the carburetor the float valve closes and the bulb firms up.-----When motor is running the bulb does need to be hard like a rock !-----So if the bulb does not go hard when pumping ,there is a problem with the carburetor float valve / fuel pump diaphragm or the fuel pick-up tube inside the tank.

racerone said:

The bulb is nothing but a " manual pump " and you should get the sensation that you are pumping fuel.---------After you fill the carburetor the float valve closes and the bulb firms up.-----When motor is running the bulb does need to be hard like a rock !-----So if the bulb does not go hard when pumping ,there is a problem with the carburetor float valve / fuel pump diaphragm or the fuel pick-up tube inside the tank.

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I was suspecting the pickup tube as well. Can you visually see a defect, crack, or blockage in the tube if you look at it? Because I didn't see anything that jumped out at me.

Another question:

If you disconnect the motor end of the fuel line and squeeze the primer bulb, are you supposed to see gas squirt out? Because I'm not.

UPDATE...

After replacing all the basics mentioned above without any results, I decided to take it to the shop. Turns out it was a broken/displaced O-ring. The only other minor problem was minimal gumming of the carbureter. The motor went in at 2200 rpms and left at 5000 rpms. Can't wait to take her out this weekend!