2001 xp with a 951 has had little use the last few years. had more use the end of last season and had a hesitation taking off but great after that. winter project to clean carbs. the fuel pump that gives an extra fuel on acceleration was not squirting gas in carbs. followed all the way to the last brass elbow mounted on carb. both were stopped up. I gave some effort to cleaning them. I could insert a small wire deep into the inlet side. I could not penetrate very deep into the carb side. I tried drilling and it would not drill out. I have some old bn44's and got elbows off of them. now both carbs are getting a squirt. back to the original ones. is there a chance there are small steel balls in there to act as check valves. I got the feeling it was something round. if it was just dried ethanol()corn oil) it should have drilled easy. both elbows were the same