cutting out at wot

[stainlesscycle]

rode today for 3 hours, was fine for first 2.5 hours..had to limp home after bike started to sputter/booowwaahh at wot - almost stalled up a big hill... i could let off the gas, and it would come back.. i first assumed it was almost outta fuel - i switched to reserve, and swapped the plug for the hell of it, and it didn't fix it..plug looked good, not lean... i got home, added 1.5 gallon fuel, and it still was doing it.. i checked flow from petcock, and it seemed fine...

another thing i noticed is: if i am wot and it's sputtering, i could pull the clutch in, and it would zip right back up. like if i took a load off the motor, it had no problems....

i haven't torn into it, but i'm assuming/hoping: main jet clogged or needle dirty. it could be a reed - but they're only 6 months old..i didn't do a buncha water crossings, and air filter is not terribly dirty...

any suggestions if it's not carb? this may be a moot point, as i'm gonna pull the carb now...hopefully that's all it is..