First make sure you have a good quality bait cast reel e.g Shimano, Diawa, Garcia, Costing about $100.or more.
Pull the left side of the reel off and you should see at least two and hopefully three high speed bearings.
1. one in middle of left side held in by a thin circular wire.
2. One on right side of the spool at base of shaft. Drive pin out & remove.
3. Hopeflly you have a third one visible looking inside on the right side butted up to the brass pinion gear.
Wash all three in brake fluid while spinning them. Brake fluid will dry in seconds; When dry, put one small drop of Hot Sauce or Kroil on each side and spin until free. If it does not spin freely repeat the cleaning process and re-oil with one drop .
Now re adjust the centrificals to two opposing and spool tension as others have advised.
IF the spool shaft is concentric (straight),
Reinstall the spool. When you push in the clutch bar the spool should spin backwards 6-10 turns with a down stroke from your finger.

If it is still sluggish you can by new ABEC Grade 5 bearings for about $10.00 each; good reels are worth it.
Tack