Reversing!

[John Cornforth]

My suspicion is that the throttle linkage could be partly to blame, as one end is fixed to the bulkhead and the other to the engine. If the engine twists on its mounts due to torque reaction from the propshaft (assuming rubber mounts) it will tend to open or close the throttle a tiny bit depending on the direction of travel. I have found the best reversing technique is to use minimal revs and avoid slipping the clutch, which is easier on level ground than when reversing uphill.