Small engine carburator setup

How to Clean a Small Engine Carburetor. Learn how to properly and safely use, troubleshoot, and maintain your lawn mower, tractor, snow blower, and other lawn and garden equipment. View How-To Articles. Browse Videos. All rights reserved. Innovations Products YOU. Change Region.

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Warranty Information. Maintenance How-To. Contact Us. How do you rebuild or overhaul a small engine carburetor? Step 1: Removing the Carburetor. Disconnect the spark plug lead and secure it away from the spark plug. Then, remove the air cleaner assembly. Turn off the fuel valve at the base of the fuel tank. If your engine does not contain a fuel valve, use a fuel line clamp to prevent fuel from draining out of the tank while the carburetor is disconnected from the engine.

Some carburetors contain an electrical device at the base of the fuel bowl to control afterfire. You can rev up the engine once or twice to prevent the buildup of carbon if the engine stays in extended idle mode. It is situated above the carburetor, and there is only a lone screw that faces outward above the carburetor.

You can see it where the air cleaner filter hose connects to it. You can also use a flat blade screwdriver to turn this screw. Turn it clockwise until the small engine almost dies. Turn the screw gradually until you find the smoothest idle. In this regard, you need to experiment a bit both ways to figure out which position of the screw achieves the smoothest idle.

You should adjust the idle adjustment screw to prevent the engine from dying during idle speed. If your small engine emits foul-smelling smoke, for example, it may be indicative of a dirty carburetor. Here are the simple steps on how to clean your dirty carburetor:. First, before starting to clean the carburetor, you should first turn off its fuel valve. Afterward, you should remove the carburetor from the engine completely. You must remove its air filter panel. Then, you should disconnect its fuel line and governor from the carburetor.

You should open up the carburetor. You should hold the carburetor over a bucket, and then remove its screw and then take off the bowl. There would surely be left over fuel in the bowl; you should simply let the fuel drain into the bucket. Then, you should inspect its needle to figure out if it is sticking or is stuck. The needle should be freely moving.

Like a small bullet-shaped device, the needle is usually made of plastic. It may also have a bit of aluminum covering. You should clean the needle valve using a carburetor cleaner, and then put the needle valve on a clean and dry towel. If the needle seems stuck, you surely need to clean it. Using a wire brush and brake or carburetor cleaner, you should carefully clean the needle. Afterwards, you can position it back and try to test it.

Next, you should spray brake cleaner or carburetor cleaner to the fuel lines throughout the carburetor. Then, you should spray the hole wherein the needle valve is set. You should also spray into the hole from where you have removed the bolt. Afterwards, wipe the carburetor with dry clean cloth. Cycle the linkage again to be sure that the linkage comes to close without any assistance. Set the mixture screw see Fig 1 by first screwing in until the screw stops, bottoms out.

Back out the screw 2 full turns. Simple Rules for low speed calibration. If the speed screw has to be opened 2 or more turns then this is also an indication of a lean condition usually requiring greater change. At times it may appear to be showing signs of richness or flooding it is really a lean condition. See pictures and notes in the tech 2 article supplied in the kit instructions, view and please understand the need to keep throttle plate as near to closed as possible so as not to prematurely expose the transition holes.

This is what causes the visible rich condition, and confirms the need to increase the jet size. Achieving the best idle at under 2 turns indicates the need for a smaller idle jet. The secret to understanding the critical nature of the carburetor set up and the advantages of a WEBER over other carburetors is the Idle circuit. This is the reason that the Weber should give a fuel economy improvement over most factory carbs along with significant performance gains.

The Weber Carburetor is a sequentially timed device to the motor like the distributor. Time taken in the setup will provide more fun later. Technical assistance is free for the first 60 days of purchase.

Units in service over 60 days may be assessed a service fee. All charges will be noted up front after a brief consultation to determine any possible defect. If the carb is out of the warranty period and no defect is determined we will estimate the possible cost of tech support or recommend literature available that may help.