Went out for a blast on the 550. These machines run well when the cylinders are all singing from the same song sheet†so to speak. Had a blast, started well and shut the choke off after about 30 seconds. I can now recommend an upgrade to these pd carbs of increasing the size of the pilots. I upgraded from 42 to 45s I thought it would make a minimal difference, it’s actually made a big difference to mainly the starting and warm up period. ☺ï¸â˜ºï¸