You said you never went through the carbs because it was running well. Well, you might have accumulated a bunch of crud in your carb's internal filter. I run an inline filter after the water separator because of how much junk I've found in those internal filters over the years. It doesn't seem to affect performance any, but does keep those little filters clean. They have been known to starve carbs before...
As for pulling the head, it's easy. Disconnect the three hoses from the head and the 12 bolts on top and voila. I just hope the guy who pulled that head last put grease on the bolt shanks like he was supposed to. I've had bolts snap from the built up corrosion on the shanks.