Float Height Check on a Suzuki GS500E

So you're wondering whether your float height needs adjustment. But you REALLY don't want to take the whole motorcycle apart just to check it. Not only that, but you know from past experience that it's hard to set that little metal tab at the correct position using the sight-along-a-ruler method.

If this describes your situation, you've come to the right place! Here's how to check your float height without taking ANYTHING apart.

Click on a picture to see a larger version.

Locate the carb drain. It's the spout just below the Phillips head screw.
Attach a length of hose to the drain. I bought this fuel-grade hose at a hobby shop that specializes in remote-control airplanes.
Make sure the fuel petcock is turned to PRI. On any other setting, the fuel won't flow into the carbs unless the engine is running.

NOTE! On 2001+ models the PRI position points toward the REAR of the bike.
Make sure the open end of the hose is above the float bowl (the lower half of the carb). Then open the drain screw and watch the fuel flow into the hose.
When the fuel in the hose stabilizes, take note of its height relative to the carburetor body.

What does this fuel level mean? Gosh, I don't know ... go ask Srinath!

Seriously, the fuel level should be at the same height as the gasket that separates the float bowl from the upper half of the carburetor body.

To "clean up" before going to the other side of the bike:

  • Lift the open end of the hose to get most of the fuel to go back into the float bowl.
  • Tighten the drain screw.
  • Lower the open end of the hose until it's about even with the other end.
  • Detach the hose from the drain spout.
At this point you can drain the fuel that remains in the hose back into your fuel tank or gas can.

Alternately, you can attach one end of the hose to the other carb and do some "fluid gymnastics" to get the air bubble out of the line before you open the drain screw.

Unfortunately, if your float height is wrong you still have to take the carbs off to adjust them. Afterwards, use this method to see if you got it right.

[Personal Reminder: Take a new set of pictures using better light!]

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