Fuel level

Just writing this to try and get my thoughts clear on the fuel height adjustment. I am using the Suzuki tool, which is basically a piece of graduated tube that screws into the drain plug for each (in turn) carburetor. The idea is that you see on the outside of the carb, the fuel height controlled by the float valve. On the RG the Suzuki manual gives the height to be 5.5mms below the line of the gasket i.e. where the float bowl meets the carb body.

Well first things first. The Carbs do not sit horizontally so there is a difference measuring one side of the carb or the other - so you need to keep the measurement to the rear of each carb. Secondly, if your pit stand lifts the bike too high then this will have an affect on this measurement.

Once you have the idea of what is supposed to happen, it should be very logical that as you bend the tab on the float, the level of fuel should move up (or down). The manual states that the bike should be idling for this measurement, but I didn't see any difference whether the bike was idling or stopped or even if the carb was connected to the engine or not - as long as the carb is at the right height and position. So most of my testing was done with the carb barely connected (just the fuel lines, and then after each change I could turn the fuel on, measure the fuel height and then quickly drain the fuel and then remove the carb, and try a different setting.

Well all of the above is great in theory, and seemed to work well on the right hand side carbs, but when I transferred this new skill over to the left hand carbs, I could not get ANY adjustment! Whether I bent the tabs one way or the other, it made very little difference to the fuel level. I also tried this with the bike running, but to know avale - it just doesn't work!

If I think about it, this means that my fuel height is being controlled by something else other than the height of the float OR bending the tab has an almost invisible affect on the level of the fuel. The float valve DOES however shut off the fuel, as nothing ever leaks out of the overflow pipes, so the float MUST control the inlet of fuel! The above two ideas seem contradictory and they are!

So why am I bothering with this adjustment? Why don't I just manually control the float height ~17-19.5mms (with the carb upside down and the float tab just shutting the valve), well because I have BALL VALVES, and these little buggers aren't the same height as the standard needle valves, so the standard float height needs measuring differently.....