Well BJ,s jetting base lines are very good however there are a few things to consider.Shiming the needle works well @ 6000 ft. and lower. Clean crisp throttle response.However at higher altitudes ,on two new 860,s and 880 all three had to remove all shims. Take a look at the DPM. Service manual gives the clue.It dosnt even start to reduce bowl pressure till 3500 rpm,s.Look at hose config. A small hole on the bottom of carbs in front of the slide is where the vaccume signal is provided.Its not untill about 6000 rpms, that full vaccume is seen and therefore shims at high altitude will run PIG rich untill it cleans up with dpm at higher Rpm,s.DPM will not lean to its full potential at cracked throttle positions , 860,s are generally 440 /450 mains at 7000ft up with no shim and EGT,s are 1150 mid and 1200 WOT..Wash and plug reads confirm this as well.Still fine adjusting and will forward the end results. Both SHR,860,s run very strong and outperform the 880.many other factors come into play,Pipes,Intake ect and the most important is Clutching,The load the clutching provides will make HUGE noticable jetting changes,As much as Two main jet sizes. Load the engine and signal increases and pulls more fuel.This is why Power jets deliver no additional fuel when running a sled on stand.No load even at Full throttle!Back to the topic ""Clutching.""I suggest it!As for SHR. I suggest it as well.Bob
