My first Saito and my first four stroke came on an old Hangar 9 80" Cub. I got the plane for an awesome deal. I was told it was RTF but the receiver crystal didn't match the transmitter. The reason I got it so cheap was that the hobby shop thought the bearings in the engine were bad and they just wanted to "unload" it. I removed the crankcase breather nipple and saturated the lower end with Marvel Air Tool oil, removed the rocker covers and did the same, removed the glow plug and shot a few drops in the cylinder and proceeded to turn it over slowly by hand and the soon thereafter it turned over smooth as silk. I installed a different receiver and changed out the aileron servos, put the fuel to it and it fired right up. This engine runs fantastic. I don't know how much run time the engine has seen and I know it has never been flown because I had to glue about 5 oz of lead to the motor mount and cowl to get it to balance. I just purchased another used Saito 56 so when it arrives I'll see how it runs. I Just took the Evolution 46 NX off of my PnP Cub that only has 2 tanks of fuel through it to replace it with a Saito 72. This whole Saito engine thing is starting to become addictive. I'm running a Zinger 12x6 wood prop on mine however I don't remember the tach readings. I may try to take some tonight if I have time.