O.S Engines 21XR-B Version II 3.5cc buggy engine
Coming from O.S. Engines is the 21XR-B Version II 3.5cc nitro buggy engine. Targeting club-level racing the re-designed long-stroke engine features an easy-to-tune 21J3-I carburettor, a new aluminium cooling head for improved heat dissipation and it is upgradable using various O.S. Speed parts for areas such as the outer and inner heads, crankcase, crankshaft and more.