Yamaha 0x66 full throttle stumble

[Skeetskeet225]

My 2000 225 HP Yamaha OX66 starts fine, idles fine & runs at low to mid speed fine but after 30-45 seconds of wide open the engine will almost die as if the key was turned off. When this happens, if I throttle back down the engine will continue to run but will do the same thing if I try to go wide open again. I put new plugs & cleaned the O2 sensor (which was built up with carbon). Is this a fuel delivery problem or something else. Any help would be greatly appreciated

[pappastratos]

Sounds like it is running out of gas. We had a 150HP that would do about the same thing. After plugs, fuel pump, filters, etc I pulled the pickup tube out of the tank and there was a piece of silicone in the pickup tube.

[99yam40]

does pumping the primer bulb help any when the problem is happening?
is the primer bulb sucked flat?
is the bulb still firm and you cannot pump it any?
checking fuel rail pressure when problem happens might help figure out if it is a fuel problem
when the VST gets low enough to suck air instead of fuel, the rail pressure drops like a rock and the injectors cannot furnish the fuel needed to run

[Skeetskeet225]

I haven't tried the primer bulb. When it cuts out it happens so fast (usually around 70 mph) it'll almost scare the s#*t outta ya cuz it feels like the engine hits something underwater. That's actually what I thought had happened when it did it the first time but then it happened again when I tried to haul a$$ again so I knew that wasn't the case

[99yam40]

only thing I can think to do is turn the key off as soon as it happens next time to keep the fuel pump from running and filling up the VST(if it is low on fuel).
then before turning the key back on, try the primer bulb to see if the VST ran out of fuel( how many pumps to get a tight bulb)

[Skeetskeet225]

I'll try to get out on the water either today or tomorrow & will try turning key off/pumping bulb and will post what the outcome is