- Location
- Aurora Colorado
SX/SXi/SXi Pro General carb question
- Thread starter ColoMike
- Start date
- Location
- Granbury, TX
(This is for Mikuni carbs) If I recall correctly, your adjustment screws should have 3 full turns of adjustment. If you start with a closed screw and open it 3 turns, you have effectively added the same amount of fuel as a half jet size larger, so a 75 jet with 3 turns out on the screw would be a 77.5.
Engine mods like a pipe can drastically effect the fuel needs of a motor, hence the need for jetting changes. For instance, my superjet high jets are 140s with my mods and stock was 130. No way you could get enough fuel just using the adjusters.
Engine mods like a pipe can drastically effect the fuel needs of a motor, hence the need for jetting changes. For instance, my superjet high jets are 140s with my mods and stock was 130. No way you could get enough fuel just using the adjusters.
Jets are for major changes in the fuel circuit. Adjustment screws are for fine tuning (typically worth no more than 1/2 jet size in total). They aren't the same and aren't interchangeable. Instead, they work in conjunction with one another. Mikuni carbs have adjustment screws. Keihin carbs are tuned only using jets.
To get a better understanding, download and read the Mikuni SBN Owner's Manual. It will explain a lot of how a watercraft carb works and help you get your feet wet. http://www.mikuni.com/pdf/sbn_manual.pdf
To get a better understanding, download and read the Mikuni SBN Owner's Manual. It will explain a lot of how a watercraft carb works and help you get your feet wet. http://www.mikuni.com/pdf/sbn_manual.pdf
Last edited:
- Location
- Aurora Colorado
There we go, coarse and fine adjustments. Now I get it