ICBM™ and EverSleeve™ for 4-Stroke Engines

Enhance the performance and durability of your 4-stroke engine with Inoue Boring’s precision ICBM™ (Inoue Boring Cylinder Bore Finishing Method). This treatment breathes new life into your prized vintage motorcycle engine, letting you ride hard today while preserving it for tomorrow.

You can ship your cylinders and pistons to us in Japan for processing, but for 4-stroke engines we also offer ready-to-install ICBM™ sleeves—EverSleeve™—that your local engine shop or restoration specialist can fit. Contact us for more information.