I'm going to be setting up a new carb on the boat come Sunday and I figgured I'd try going about it the "right way" rather than just making changes, reading plugs and fumbling around through trial and error.
To set up the powervalve, I know I need to make sure I use a powervalve that has a lower vacum rating than my vacum at cruise. But how much lower should it be? As a hypothetical, if I was pulling 6 lbs at a 3500RPM cruise, would I go with a 5.5?, a 5? How far in the powerband do I want to take my reading for where the PV should open? If I spin to 5k WOT where would I consider my cruising RPM? highest possible without the secondaries? whatever feels comfortable for the motor, or base it off of my actual typical cruising MPH?
Prior to setting up the PV, I'll need to tailor the idle circuits. I've always used the tach as my gauge for this routine. With the primary and secondary throttle shafts set so that I'm not bypassing the idle circuit, aim for the highest RPM without an off idle stumble. Is this an accurate way of handling things? Could vacum be used as an indicator for this portion as well? If so, set it up to pull the least amount of vacum, or the most?
This is stuff that a lot of folks would consider remedial, but I'd appreciate any input that the pros such as Info, Gofast, and the like can offer up.
I've always had good luck with more "shade tree" techniques on cars where you could just go haul ass around the block to check your work. But after dicking with setup and tuning during trips, I'd rather take a more direct and proven approach to nail things down with a higher degree of confidence.
Thanks in advance for the input,
Chris