Pulley for starter Mechanical Buffalo (MB) - Model badang Starter
Dimension  : 3.7" x 1.5" x hole 1.7"
Weight          :  100 gm
 
Interpretation and Assumptions:
"3.5 inches": Likely refers to the outer diameter (OD) of the pulley or a related dimension.
"A x B": Could represent other dimensions (e.g., bore size, width) or model-specific identifiers, but without clarification, I’ll focus on the 3.5-inch dimension.
Pulley Starter: Typically a recoil starter pulley used in small engines like those from Briggs & Stratton, Homelite, or Poulan.
 
Relevant Information:
From the web results, several recoil starter pulleys are mentioned with dimensions close to 3.5 inches:
Briggs & Stratton Recoil Starter Pulley for 3.5-3.75 HP Classic and Sprint engines has a diameter of 12.4 cm (approximately 4.88 inches), which is larger than 3.5 inches.
Phoenix Steel Drive Pulley at Tractor Supply has a 3.5-inch OD and a 5/8-inch bore, but this is a drive pulley, not a recoil starter pulley, so it may not fit your needs.
Stens Starter Pulley for Homelite models has a 2.5-inch OD, which is smaller than 3.5 inches.