Fuel level check?

[pinholenz]

Looking at the Haynes manual it gives a a method setting the float height at 36mm, and then a fuel level check with the external measuring hose for the actual fuel height belo the gasket. (See also page 106 of the 11J service manual.)

Both require bending the float tang to adjust height/level.

1. Why do both tests.? Why not just do the fuel level check and be done with it?

2. Why would you put the carbs back into the bike to do the fuel level test? Why not set the carbs level on a bench with the measuring pipe in place, hook up a pony tank at a decent height above the carbs, introduce fuel and measure what happens? This way, any adjusting that needs to be done is relatively easy and accessible.

[Rikugun]

Set the float heights and check the fuel level to verify the heights have been set correctly.

Measuring either one has it's pit falls and can be messed up giving faulty readings. Others may disagree but I feel the fuel level is a more accurate measurement. The manual does say to run it a few minutes with the gage connected so maybe it needs to normalize under running conditions? Perhaps the pressure difference between gravity feed and pump makes a slight difference in the level? You'd also need to ensure it's sitting at the same attitude on the bench as when installed on the bike sitting on the centerstand. 

[The Prophet of Doom]

1. Why do both tests.? Why not just do the fuel level check and be done with it?

The  float height test allows rapid iterations of adjusting and checking,.  It would be an almighty pain in the arse having to fill your carb with fuel. Then drain and adjust and check it again.  Perhaps several times till you get the height just so.  But it doesn't check that the valves are working, floats floating etc.

[pullshocks]

In addition to what the others have said, when you do have to make adjustments, it is very tricky to bend the tab just the right amount.  In other words, to change your float height by 1 mm requires just a very slight bend.  Measuring the float height before and after tells you whether you have overdone it.

But from my recent experience checking on the bike is what you need to do.  The 36 mm got me in the ball park but did not translate to ideal fuel level in both carbs

Very time consuming but made a huge difference.