I bout a cherry 2000 YZ 250 from a guy very little wear. It has about 15 hrs on top end. It does have a rough throttle cable slightly kinked still works though. Anyways when accelerating and gets to the powerband its kind of jumpy like it wants to hit but won't. It's smooth on the top side but feels a little lacking on punch. All I've read I'm thinking powervalve or reeds. The bike ran fine when put away for winter then this spring he cleaned the carb and now it's doing this? So would it be the powervalve from sitting all winter? He's said he thought it was clutch cable or throttle cable as. Which that is why I'm asking this question can a sticky or kinked throttle cable or bad clutch cable cause it to be jumpy at powerband and not want to kick in and be a little lacking on top end. There's no bucking and jerking in forth and fifth gear just 1St-3rd!