It does sound as though the belt is creeping some. If you had an assistant, you could verify this. There is a spec for the measurement on the spring, but basically you just need to bring in an idler a tad. A 180 will either have a small v idler near the drive pulley that is slotted in the frame or the rear one of the tandem pulleys on the tensioner arm. Perchance does the belt look new as if it was replaced? A number on the belt may tell you if it is proper.

Thank you for the info... It has the tandem pulleys & the belt looks to be used but in good shape. I couldn't read any numbers.

Thank you for the info... It has the tandem pulleys & the belt looks to be used but in good shape. I couldn't read any numbers.