Clear Tube Method for Troubleshooting a Motorcycle Carburetor and Checking the Float Height

The most precise method for adjusting a motorcycle carburetor float is with a clear tube. Without the need for carburetor removal, a clear tube test for float height or needle and seat performance can be done in the frame. This is a quick, accurate troubleshooting procedure that does not require gauges or time wasted removing the float bowl or carburetor. We can avoid opening up a carburetor in desert dust storms!

Our Honda XR400R, featured in this video, is a typical late model dirt motorcycle. The carburetor is difficult to reach and service. Like most other newer motorcycles, carburetor removal is a major chore. Many newer bikes have a maze of crankcase emissions devices, suspension components, exhaust tubes and air box obstacles in the way.

For any carbureted motorcycle or engine equipped with a side-draft carburetor, the clear tube float height check and fuel flow test can be a major time saver and pinpoint troubleshooting tool. "100 miles from nowhere" on your motorcycle adventure, a short piece of clear plastic fuel hose and a tie strap can provide a view of fuel flow and float performance without removing the float bowl! Motorcycle pit teams, global travelers and dirt riders need to master this technique.