While the airbox was off, I again check all the pressure hoses to the carbs. Oh, what have we here. BIG leaks in the pressure lines to the carb bowls. Two leaks like this. Not observed before because the fittings were tied to that fuel line and the split was against the fuel line. The pressure line had to be removed to see the splits. Reason for split, use of an "inch" fitting instead of "metric" fitting. Stressed the hose causing the splits. Ordered new Rotax replacement fitting and new hose. All new parts fitted and checked. All OK. Ran engine. Still did not run right!!! Ran smooth up to 4200 RPM when RPM smoothly drops to 3200 RPM at which time it runs back up to 4200/4300 RPM and drops back down, repeat cycles.
