I put a new starter in but sometimes when i start it it just clicks is this a bad starter

 

did you replace the solenoid too? If not, that could be your problem. It's the little thing that looks like a motor kinda piggy-backed onto the starter motor itself. I know they sell them seperately, so you might not have gotton it and had to use the old one.

What happens in a starter is when you turn the key, the solenoid pulls back, this actuates a fork that engages the starter gear. When the solenoid pulls, it also makes a set of contacts(kinda like a relay) and send power to the starter motor itself, that's what makes it spin. So you see, if the contact in the solenoid is bad, it won't power the motor. Also, Just check to see if the big copper starp connecting the starter motor and solenoid is tight. if not, you aren't sending power into the motor.