- Start on a runway, with the engines running.
- Things to check need to be checked. The complex the plane, the more things there are to check.
- I would imagine what is happening here is your throttle quadrant updates after you move the first lever, so if you have your mixture at cutoff, as you advance the throttle, lever positions are updated, and you effectively cut the fuel. Just a guess. Ensure all throttle levers are where they should be, especially if you are starting on the runway.
- You don’t mention the plane, but at a guess I would say you have bound the wrong setting to your flaps lever, so rather than incrementally raising/lowering flaps, you are bouncing between zero/full flaps at a single press.