I've got 1981 550 Maxim When I started up with the choke / fuel enrichment system on full the idle goes up to around 4,000 stays there for at least a few minutes And when I cut it back it usually stalls If I start it up again and just drive it after 5 or 10 minutes it idles just fine I've had all the carbs apart and the Jets all look super clean and the bowls too I haven't broken down the rack yet but is that probably where the problem lies?