Merc 40 cutting out full throttle..any help?

[Killin Time]

I have a 2001 40HP merc 2 cyl that just started acting up. If you run WOT it will start to cut out after about 30 seconds or so. RPMs drop off to about 4500 or so like it is starving for gas and then pick up again after about 15 seconds. If I run it at 5000 (vs 5500 WOT) it doesn't have the problem. I have checked the fuel filter, looked at the float bowls to see if there was any junk at it all looks fine. I have even used a fresh tank of gas to see if that made a differnce. I have always fogged and used seafoam in every tank since I got it new.

Anyone else seen this or have any ideas?

Thanks
Don

[Twitter]

Possibly the fuel line from the tank has a leak and is sucking air. Check the hose and all connections.

[fishin789]

i had that happen to my motor once. turns out the vent on my gas tank wasn't working right. i loosened the cap and it ran fine.

[upnorth]

check to see if the bulb is collapsing. If it is it is probably a venting issue.

[Killin Time]

Thanks, I will check it tonight as I am heading out for the crappies.