Am mounting a 1.20 in a Velox Revolution II. Will mount it inverted and am looking for an in-cowl inverted muffler for it. The engine started right up in the test stand with the recommended 15x8 prop. Seemed very steady with good transition, etc. Did not tack it but if it performs well in this application, will be very pleased, especially for the price. 3.1 hp for $90 on eBay can't be beat. Will let everyone know how it turns out.