I just installed a MAC 4-1 exhaust on my 550. The install went well although 5 or 6 more (very small) hands would have been a big help. The carb jets---per the advice of many---were not changed.
The bike was running fine before the install and still runs fine, but after only a few minutes of static running the header pipe on number one cylinder is a very dark blue while 2,3, and 4 are still gold-to-bluish. The total running time was about 10 minutes---3 warm-ups of about 2-3 minutes each. Cool down in between.
Any thoughts?
Thanks.