4 SPEED TRANSMISSION OVERHAULING REPAIR SERVICE KIT ROYAL ENFIELD BULLET MOTORCYCLE. NEW 4 SPEED TRANSMISSION OVERHAULING SERVICE REPAIR KIT. The above shown transmission kit is SUITABLE FOR :- 4 sp ROYAL ENFIELD BULLET bikes. This is best if you are servicing, repairing or overhauling your bikes transmission kit. Please refer to the pictures before finalising your purchase. Best for restorations and modifications.