Hung up carbheat

[Jeff Orear]

Hello Coupers:     We are having trouble with the carb heat on our 415C  C85.  On runup, the carbheat can be applied to its stop, and we get a good RPM drop.  But in flight, when carbheat is applied, I can only get the carbheat to pull back about half of what it does on the ground.  This happened again to me last night, and several tries failed to gain full carbheat.   We have tried to lubricate the cable, but this did not help.  Anyone else have similar trouble?  Any help would be greatly appreciated, as not being able to apply full carb heat does not make me a happy couper.       Regards, Jeff Orear N93966