Brief Description: Rotax Service Bulletin SB-014-055UL
Today I carried out the intent of Rotax service bulletin SB-914-055UL. The heavy maintenance manual calls for the circlips of both carburettors to be installed in position 2 for this series engine, I found the 2/4 carb (left side) had the circlip in position 3 & the 1/3 carb (right side) circlip was in the number 2 position. As I understand it, a higher numbered circlip position enrichens the fuel/air mixture at low RPM but has little effect at higher power settings. The service bulletin states that the circlips should be replaced in the positions as found so that is what I did. As it turns out, this was exactly the case with PGC's engine and they have adjacent serial numbers. One issue I had was the "B" nut of the left fuel line was so tight, when I was undoing it to remove the pipe, the fitting in the carburettor body loosened (couldn't get a spanner on it to hold it) so I needed to remove it, clean it, re-install with Loctite 243 and torque to 10Nm.
