My Carbs Are Leaking! What To Do

There are only a few reasons why your carburetor could be leaking.  This tutorial is for you if your carburetor leaks from the bottom overflow line (bottom pink hose).  All carburetors need fuel to operate, but the bowls can only hold so much, and when it reaches its limit, the float needle and seat seal stop the fuel flow into the carb.  If an obstruction gets in the way of this seal the carbs continue to fill with fuel, and the excess begins to flow out the overflow tubes on the bottom of the carburetor. Below are instructions to remedy this.  If this series of steps does not work, or your carburetor is leaking from a different location please give contact using the email or phone number provided at the bottom of this page. 

***Do Not Perform This procedure While Your Motorcycle is HOT***

Step 1.  Turn your petcock to the off position.

Honda CX500 motorcycle petcock in the off position.

Step 2.  Place towels or some rags under the carburetor to keep fuel off your motorcycle, and loosen the drain plug at the bottom of the float bowl with a 17mm wrench.

Loosening the Mikuni drain plug with a 17mm wrench on a Murray's Carb Kit.

Step 3.  Remove the drain plug by hand, and let the float bowl completely drain.  To avoid fuel getting on your hands wear gloves.

Draining fuel from a Mikuni VM carburetor float bowl.

Step 4.  Put new towels or rags down if necessary for this step.  Turn the fuel on, and while it drains out of the bottom of the bowl give the bowl 4-6 light taps with a plastic or rubber handled screwdriver. Quickly turn the fuel off after your done tapping the bowl.  The flow of the fuel and vibration from the tapping should dislodge any small debris between the float needle and seat.

Tapping the float bowl while draining the fuel to dislodge any debris stuck between the float needle and seat.

Step 5.  Reinsert the drain plug by hand, and be sure the o-ring is in place.  Do not torque this plug down.  It seals to the o-ring, so snug it with a 17mm wrench until it seats.  Now you can turn the fuel back on and test to see if the procedure works.  If the carburetor continues to leak fuel contact us using the email or phone number below.