adjustble spray bar... can some one explain
 

well my RB V12 R3 has an adjustable spray bar. this is my first engine that has this adjustment can some one explain to me what effect this adjustment has. no problems with the engine so far just curious.

If you are talking about 1 LSN screw it will adjust the mixture adjustment at lower rpm, in normal words it will adjust the acceleration.

If you are talking about 2 screws (1 brass color in the housing of the carb and 1 in the slide) then both do the same. Adviseable is to keep the large brass one equal to the housing and just use the one in the slide.
If you screw in the one as much as you screw out the other one the adjustment stays the same but you did move the spraybar to another spot in the airflow what can result in a beter result but it can also get worse....

the manual didn't say much about it, so thanks for the explanation ... i wont mess with it then