Flyboy Dave,

Here is a quick summary of the differences between the Hanno and the standard OS 61 RF:

1. The Hanno has an integral fuel pump that allows remote (e.g. on the CG) fuel tank location

2. The Hanno has sturdier bearings

3. I also believe the Hanno has different timing and compression to deliver more torque and raw horsepower than the standard 61 RF. The recommended props for the Hanno are the APC 13x10 and 12x10W.

4. The price for a new Hanno was 3 times the price of the standard RF, which is why I bought mine second hand!

Basically, the Hanno was designed to be a pattern engine, which it did very well. Up until the engine displacement restriction was removed, Hanno powered ships were still doing well against the YS 120 powered birds.

The Hanno had many advantages over the YS 61. It was very user friendly, where as the YS, with it's pressure regulator was quite cantankerous. It was the last, most powerful, and best 61 sized pattern engine.


Rob