Hi Steve

Sorry to hear you experienced a problem with your RCV120SP.

This is not common, and I would assume that the main needle on the carb is faulty, hence the lack of friction. Obviously your piece of fuel tube does the trick, however if your engine is still within warranty, we would be happy to replace your needle and spring.

Sorry for any inconvenience caused, but please pm me with your warranty details

Best regards
Laurenne