Zenoah G260RC engine is a 25.4cc (34mm bore, 28mm stroke) performance machine. The engine features a stronger intake manifold for better thermal isolation, a red silicone spark plug cap, new blue gaskets, wider intake and exhaust ports, a lighter 34mm piston and thinner ring for reduced reciprocating mass, and improved transfer port matching between cases and cylinder. This engine offers serious performance. It features a 4 transfer port 34mm cylinder, Walbro WT-603 carburetor (15.88mm bore, 12.7mm venturi, independent high and low jets) in your choice of linkage configuration, lighter flywheel, re-designed "hemi"-style combustion chamber, and full-circle crankshaft. Includes installation instructions.