The cowl doesn't mean much. It could be mounted a little off by it's self. Also I wouldn't necessarily trust measuring from prop tips unless I averaged the measurements with the prop rotated 180. Ever look edge on at a prop when the engine idling? A quarter inch wobble is not uncommon on a 10 to 14 inch props.

Itried to maiden a Twist 150 Monday. It has a Saito 180 in it. Iwent out on the runway and taxied it around, getting a feel for it and the, it was time for the take off. I've only flown tail dragger's for the last three years and all have been four strokes. Easing on the throttle while using some right rudder, until the plane has air speed and the rudder can control it is kind of second nature now. HOWEVER. Monday was an experience. I started my roll our and when I went to about half throttle, it was pulling pretty good to the left and I had to use a bit more right rudder than normal, however when I kicked the throttle some more, the rudder really took control and the plane did a 90 degree right turn and was off the runway before I could shut it down. No damage, but it left me kind of shaky. Ihaven't lost a plane like that in three years. My conclusion was that the 180 is a brute when it comes to torque. It required a lot of right rudder to keep it straight, but when the huge rudder took over, it was pointed in a much different direction than the plane and off into the weeds I went. Throttle control is something I'm going to have to really practice with this plane.

Don



Four strokes have a lot of low end torque.