Strange behavior on Yamaha 50 TLRD 2005

[metricyamaha]

I have a 2005 Yamaha 50 TLRD on a pontoon boat. The engine starts right up, and it idles normally. I warm it up on idle for a few minutes before I head out. After taking off, after 2-3 minutes, the engine dies when I open the throttle. After this, it restarts right away, and then dies in a few seconds. I have to use the emergency choke (red knob) and restart it a few times. After that, the engine runs fine.

The carburators were cleaned a few months ago, checked the spark (7/16th gap) & spark plugs, all look nice. I think it may be fuel related.

Any advice please?

Thank you!

[99yam40]

check fuel pump and for air leaks in fuel system

[metricyamaha]

Thank you for answering!

I don't think it is a fuel pump issue, because the primer bulb is always hard.

I changed the fuel tank for a bigger one, and I added a small inline clear filter so I can see if the gas is flowing.

I think that even if the fuel pump wasn't working, it would still run fine with the primer bulb.

[spidermike55]

hi, i have same engine and mine is doing same thing. Did you determine the cause?

[boats.net]

If have to choke it to keep running then need to remove and clean carbs.

[robert graham]

Get carbs cleaned and install a fuel/water separater type canister filter(Walmart/Attwood $27) to help prevent water/ethanol/debris in carb jets.

[metricyamaha]

I find water in the carbs,the "new"tank have small hole on top.