The next area for fuel control is the carb float needle. If your gas valve tests good, or has now been repaired or replaced and tests good, we will move on to the carb float needle.
The fuel valve controls fuel when the bike is running or when the lever is in the off position. The carburetor float needle stops excess fuel at the float bowl.
The needle has 2 tabs or ears on the end that enable it to sit securely in a notch on top of a brass or plastic float {see photo below}.
In the absence of gas, the float moves down, allowing the needle to let gas in, filling the bowl to a specific height. The rising float lifts the float needle into the needle seat, sealing off the gas entry point.
When a carburetor float needle gets corroded from old gas, or fails, it can no longer move freely into the needle seat. It can get stuck outside the seat, effectively, in the open position. This allows gasoline to overfill the carb and run down into, and flood, the engine.
See Why is fuel inside your engine bad? on the previous page.
The float may also fail.
Floats can develop pin holes or minuscule cracks that let fuel inside the float. This makes it heavy, no longer buoyant, so that it can no longer “float” up and down. If it can not float up the fuel will continue to enter through the float needle.
The float needle and seat together, are often called a float or needle valve assembly.
The carb float bowl needs to be removed so that you can check the condition of the float and needle. I did not have a DR200 carb to demonstrate but I had a set of old crusty Honda CB450SC carburetors to work with.
You may try to do this with the carb still on the bike. I took the carbs off & put them on the work bench to make it easier to photograph.
If you do take the carb off the bike, make sure you drain the float bowl before taking it off. Just loosen the drain screw and let the fuel run down the drain hose.
Check the Carb Jetting page section Before You Begin for a list of what you should have on hand.
Got everything? Now you’re ready.
Locating the Carb Float Needle
First, remove the screws that hold the float bowl to the carb housing. If the bowl does not come right off, you may need to thunk it with the handle of your screw driver to dislodge it. Now you can see the float.
It is attached to the carb body with a long thin pin on which it pivots or floats up and down {see photo at right}. You need to tap this pin out. Place the tip of a pick or super thin screwdriver on the end of the pin and lightly tap the handle with a small hammer.
If your tool is too large to tap it all the way out, gingerly grab the other side with pliers or vise grip. You want to hold on to it but not grip it so tightly that it becomes deformed in some way. It needs to go back in when you are done. Holding the pin in the plier or vise grip jaws, tap the tool with the hammer to pull the pin the rest of the way out {see photo below}.
Once the float pin is removed you can lift out the float. The float needle should be in its notch on the float. If it is not there, look in the needle seat.
The seat is in the carb housing, under the float, just in front of when the pin was. The float needle may be stuck in there. Use small pilers to grip the end and pull it out. Don’t worry, it can’t fall all the way in.
The 2 side-by-side photos above show the needle in the seat (left) and an empty seat (right).
If at any point things seem really cemented in there, use a little carb clean or lubricant to loosen them up.
Next, check to see if the needle slides freely in and out of the seat. If it does not, that is most likely the source of your fuel problem.
See cleaning a carb needle & seat for more information and photos of how to clean the float needle & seat and ordering replacements if you need them.
Leave Carb Float Needle and go to Fun Stuff