So let me ask,, how do you increase or decrease the engines vacuum? What I’m saying is no matter what the actual engine vacuum is that if you set the gauges up to read the same on the work bench and then attach them to the vacuum ports and then adjust the throttle bodies to read the same across the board you will have sync’d your throttle bodies. On my fjr depending on the day I see between10-12 inHg at the gauges, is that the actual vacuum ? Don’t know w/o actually calibrating the gauges on a master gage. I guess I’m not sure of what you are trying to tell me.
So do you just take your gauges off the bench put them on your bike and just adjust the throttle body vacuum to 9.8inHg across the board ? what about the “master” #3 t-body ? What gauges do you use ? Just tryin to understand here.
the vaccum of ANY engin is a Direct result of rings/ valves/ compression etc
a new NOT broken in enginw will NOT read as same engine Broken in ...............
nor will it read after Uv achieved best reading on 1 engine...........SAME reading on another
the gauges first came out when the CB750 air cooled engine was introduced............
the headache religion busting circumstance was at idle a minimun reading was suggested
yet by time the gauges were near the same the engine had gotten HOT & HOT idle resulted in
very different idles that flucuated greatly
U are by bench or mityvac setting to a false ZERO ................
set the same at a min usually resulted in an advantageous of idle throttle response
instead of a stumble
out of adjusted in many instances does NOT result in a a Stumble
a proper adjustmen does NOT help anywhere else other than idle
No Less it DOES NOT result in a power gain thru out RPM range