Carb Float Needle

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}.

Carb float with needle

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 not 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.

Location of carb float pin

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}.

Carb float pin removed

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.

Float Needle in the seat

Float needle seat - empty

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.

Cleaning the Carb Float Needle & Seat

Clean the needle with carburetor cleaner and a soft toothbrush or cloth.

Clean carburetor needle seat

Cleaning the carb needle seat

Soak a cotton swab with cleaner and buff the seat and rim. Once both parts are clean, the needle should function properly.

In the CB450 set of carburetors we used for the photos, the end of the carb float needle that sits in the notch in the float was corroded. The photo below shows the carb needle we removed next to a new needle.

New and old float needles

So in the CB450SC carbs, the needle moved in the seat easily, but was no longer hooked to the float. The float moving up and down no longer controlled the needle movement and therefore the needle no longer controlled the fuel supply.

If your needle is damaged in this or some other way, it needs to be replaced. You can purchase a needle and seat together as an assembly, but sometimes, especially with older bikes, all you can get is the needle.

Replacement Parts

If you do have to replace the float valve assembly. K&L Supply has a float valve assembly available for your 1996 DR200SE. It is on page 223 of their 2009 catalog. Needle Valve Assembly, OEM Suzuki part number 13370-44500; K&L part number 18-4666.

Note: K & L Supply does not sell directly to consumers. The majority of dealers and motorcycle repair shops carry K&L products. You should have no trouble locating a dealer.

If you do run into a problem, you can call them, 408-727-6767 to locate a dealer near you.

If the seat looks good, you may want to replace only the carb float needle. The K&L part number, for the needle only, is 18-8957.

If the float needle and seat look good, the float itself may be the problem. As its name implies, it should be watertight and "float". Use a container of gasoline or water to put the float in. Try to hold it under the surface. It should be buoyant. If it sinks, you need a new one. You should be able to easily get one at a local Suzuki dealer. It is the same float used in the current 2009 DR200 model.

Do Not Forget

After all repairs have been completed, remember to change the motor oil and filter. Be sure to check the airbox for fuel puddling and empty drains on the airbox bottom.
Also, it is a good idea to be sure that on any carb float bowls that are equipped with a drain nipple, that they have the hoses going from the bowl nipple to the ground. This prevents any fuel that is trying to escape, to reach the ground. Avoiding any electrical components or hot pipes along the way.

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