ORIGINAL: flyinwalenda
Pete,
Are the specs correct in that the 15cc is almost 10 ounces heavier than the 10cc and only 2.5 ounces lighter than the 20cc ?
Yes - the specs are correct. Please remember there is a significant case size difference between the 10cc engine and 15/20cc engines. The 10cc engine is buillt into a 46 size case while the 15/20 cc engines are built into larger 61-91 size cases, with mlarger bearings (one of the greatest adders of weight to an engine) larger crankshafts (steel adds weight) and they both have a steel liner.
Pete