Levers have fitting and sometimes the way they mount can cause the clutch cable to get bound up. Before trying the old levers try letting out your clutch tension so that the clutch does not engage as soon as you pull the lever. adjust it so that it engages closer to where your hand is almost squeezeed tight.I haven't tried the old levers because I can't find them... I'm going to go look again. Why would the levers cause this?