O.S. MAX-R21 - Racing Engine Most of the parts have been newly designed based on the O.S.SPEED R2102, which is a high-end model, to achieve both the ease of handling and the high performance required of the 21 Racing Basic Engine. An affordable price is one of the attractions. The perfect power plant for rookies and club racers Newly developed crankshaft and piston / liner with the capability to upgrade later to a spec-class performer RP7 Turbo glow plug 8.5mm carb reducer Exhaust seal ring Dust cap set Specs: Displacement: 3.49cc Output: 2.71hp @ 32,000r.p.m. Bore: 16.08mm Stroke: 17.2mm Practical r.p.m. Range: 3.000～41.500 Weight: 350g
