Drive Belt 725 for 30 series torque converter. TC replacement belt used on many kits as well Trailmaster and Hammerhead mid karts. Some of these use the 669 belt check your old belt. Center to center spacing for This belt is used on older Hammerhead 80T and Trailmaster MID XRX Karts with a 6.5HP engine.driver and driven pulley needs to be between 6 5/8 inch and 6 11/16 inch Replaces parts number 9.100.018-725 This belt is used on older Hammerhead 80T and Trailmaster MID XRX Karts with a 6.5HP engine Package including: 3 x Go Kart Drive Belt as image display Product Description Drive Belt 725 for 30 series torque converter. TC replacement belt used on many kits as well Trailmaster and Hammerhead mid karts. Some of these use the 669 belt check your old belt. Center to center spacing for This belt is used on older Hammerhead 80T and Trailmaster MID XRX Karts with a 6.5HP engine.driver and driven pulley needs to be between 6 5/8 inch and 6 11/16 inch