Belt Drives 47-31 SE-4 11mm Primary Belt Drive Kit for Harley-Davidson

The Belt Drives Ltd. 47-31 SE-4 is an 11mm enclosed primary belt drive system designed for 1965-1984 Harley-Davidson Big Twin models with electric start and 4-speed transmissions. This proven design has been trusted by riders for decades as a reliable upgrade from traditional chain drive systems.

Complete Kit Includes:

• 1-1/2 inch wide, 99-tooth Gates belt for superior durability
• 31-tooth drilled and tapped front pulley (spline shaft)
• 47-tooth rear clutch basket
• Idler bearing kit with tensioner bracket and rollers
• Front pulley nut and washer
• Inner and outer belt guides
• Starter ring gear

Key Features:

• Hard anodized aluminum pulleys provide superior wear characteristics
• Hardened clutch dogs and chrome-moly carbonized steel bearing surfaces
• Transfers power over 10% more efficiently than chain drives
• Drastically reduces noise and vibration compared to chain systems
• Works with stock hub and clutch pack or optional BDL Competitor Clutch
• Compatible with both kick start and electric start models
• Made in USA

This 11mm belt drive system incorporates your stock hub and clutch pack directly into the belt drive pulleys, making it a comprehensive yet straightforward upgrade. Belt drive enthusiasts consider the 11mm configuration the optimal size and combination for all-around riding performance and dependability.