Just a little carb tuning help pls

[rotorhead]

94 sl750 with SBT motor and added fuel pump plumbed in as SBT recommends. Question on the adjustment of the idle mixture screws....the stock baseline setting has the #1 cylinder turned out greater than the #2 and #2 greater than #3. Is this because of the lone fuel pump used? Will the added pump change these settings due to increase in fuel flow? If I choose to add a third pump will this affect the settings even more?
Any help is appreciated.

[Rider X]

The screws are base lined like that due to the fact the front cylinder runs hotter than the other two. and your rear cylinder runs hotter than the center, on most boats.
Adding fuel pumps does nothing to change this if you do not change the return line jetting.
If you stay the same with return line size then your pressure is the same no matter how many pumps you install per cylinder. The pressure is still regulated by the return line restrictor and if you find your carbs flooding easily, your restrictor is to small, if you cannot keep enough fuel in there and run lean, it may be to big. Fuel pumps only pump at the rate that it is rated for. I hope this makes since.
Think of it like a hose. You have small holes in a hose. If you turn on a pump and pump water through the hose with the other end completely open, you will get very little out the pin holes in the hose, but if you pinch off the open end, and pump again the hose fills, the pin holes shoot water out at a constant stream. Make since? So no you still want to use the baseline SBT sent you and then run the motor rich for the break in, then tune after break-in.

[rotorhead]

Thanks X Man.......Good analogy and is does make sense. I did'nt even think about the forward cyliinder running particularly hotter than the rest but I can believe it. They do get hotter than Georgia asphalt in August.
Thanks again.