Introduction: Fixing a Carburetor Needle Valve on a Small Engine

Is there a lawn mower, go kart, or anything with a small engine, that has been sitting for a while and just isn’t getting gas through it? Well there is a good chance the needle valve is stuck in the carburetor. In this essay I will explain how to take the carburetor apart and fix the needle valve. This is just one way that could fix a small gas engine.

Step 1:

To start this off, locate the carburetor. For this step the gas should be on. On the bottom of the carburetor there is a bowel with a bolt head on the bottom of it. Get a socket that fixes the bolt head and loosen. (turn it counter clockwise) Ounce the bolt is really loose, pull the bowel down to create a small gap between the bowel and the carburetor. If there is no gas coming out of the gap, finish taking off the bowel by taking out the bolt the rest of the way.

Step 2:

After the bowel is off make sure the inside of the bowel is dry. (If so continue reading this) The gas should still be on. The float is now visible and it is usually white. Depending on what type of engine and how the needle valve is connected to the float, the float will either move up or down or it will be a little stuck. If the float is stuck up lightly pull down on it. Doing this should unstick the needle valve, and gas should start coming out. If gas is coming out turn off the gas. By chance pulling down on the float and just moves and there is no gas coming out move onto the next step with the gas still on.

Step 3:

With the gas off or if there was no gas coming out and the gas still on, find the pin in the back that is holding the float onto the carburetor. Push the pin most of the way out. When the pin is almost out hold onto the float and pull the pin out the rest of the way. With the pin, out the float should be free. If the gas is still on be prepared to shut it off. Gently pull down on the float and which will release the needle valve and the float and valve will come off. When the float comes off with the needle valve and the gas is till on, gas will start coming out. Shut off the gas.

Step 4:

Now that the float and needle valve are out, take some carburetor cleaner and spray it up the hole where the needle valve goes. After doing that spray some on the needle valve as well. This will clean the varnish off of the valve and inside the carburetor. Inspect the float and the needle valve to make sure there are no holes in the float or nicks out of the needle.

Step 5: Step: 6

Once everything is cleaned up it is time to start putting it all back together. Line the needle valve up with its hole and slide it and the float back up into place. Make sure the holes that the pin goes through the float and the carburetor are lined up and slide the pin back in. When the pin is in let go of the float and this should allow the float to move up and down.

Step 6:

When the float and needle valve are back in place turn the gas on. Without holding onto the float gas should be running out. Then push the float all the way up the gas should stop running out. Then let go of the float and the gas should start running again. Do this a few times to make sure the needle valve does not stick, then shut off the gas. If the needle valve sticks again, go back through the steps and clean it again. If it looks like it is working go move onto the final step.

Step 7:

Finally, with everything is working right, inspect the bowel and clean it out if needed so. Slide the bowel back up into place and then put the bolt in the bottom. Begin tightening the bolt. Make sure the bowel is lining up to where it is supposed to go and tighten the bolt the rest of the way. Do not over tighten the bolt just get it snug. Turn the gas back on, and check for leaks. If there is a leak tighten up the bolt just a bit more. If there are no leaks the carburetor needle valve is put back together and fixed the engine should start now.