Actually, I had a spill during the TD at Snett before the races and the engine was running horizontal for less than 20 seconds at idle revs. The engine started to loose power progressively during the races. Opened the engine and the big end bush of the front rod was loose and worn out to copper. Veery lucky I didn't blow the engine!
The only explanation is the 20 seconds horizontal. So Chaz, let me know if you find a suitable switch please.