This is normal with Barnett because they are a little thicker than stock.Just make sure you have the cable adjusted a little looser than you had it adjusted with the stock clutch.
What is the best way to do a stroker?Use the wiseco kit that has the pistons and gaskets or just use the wiseco stroker crank, port the cylinders, and miil the head or domes for the pistons to clear?
Is the fire weak,(orange) not blue?Find out what your compression is?Make sure the pilot jets are not clogged?If you have the tors on it,unplug it at the black box on the left hand side(statorside) under the gas tank.
You might be able to go up to 280 or 290 mains.If the bike is running great on the 260's,not popping or falling off the other end.I don't think bigger carbs going to help you.