Introduction: How to Clean a Carburetor on an Engine
Video tutorial on how to clean the carburetor on a small engine. Styles and removal processes will vary, here I’m working with a snowblower. Some engine may or may not have a cover, air filter, other items in the way, etc. Over time the carburetor becomes dirty from either the fuel are particles in the air. This can cause increased fuel consumption, erratic idling, erratic running, hard starts, no starts, won't stay running, decrease in power, or the adjustment jets won't function.
- ratchet set
- carburetor cleaner (used in the video is Permatex Throttle Body, Carb & Choke Cleaner #80279)
- thread locker (used in the video is Permatex Permatex Medium Strength Threadlocker Blue #24200)
- fishing line or torch cleaning tips
- new seals or gaskets
Step 1: Removal
If they are equipped with an intake manifold such as this model, they can be remove from the intake manifold, or the intake manifold can be remove from the engine block. Normally I like to take this intake manifold as it can suffer from some build up inside that needs to be cleaned. The bolts directly on the block can sometimes be seized, therefore a hand impact driver can be used to remove them. You may find the carburetor or intake manifold stuck which is perfectly normal, just apply a little pressure and it’ll pop right off. Remove the fuel line and remove the metal push rod for the throttle.
Step 2: Disassembly
Find a safe area to work so we don’t risk the chance of losing any small parts and then disassemble the carburetor. Disassembly processes will vary depending on the make and model of carburetors. Remove the two carburetor adjustment jets, not all carburetors have two jets, some have one. You can determine it’s existing setting by turning the screw in until it stops and count the rotations. Remove the retaining sleeve holding on the float bowl. Fuel can still be present in the float bowl which will dump out, so be prepared for that with a pan. Remove the float bowl, you may find it’s stuck but a little force will easily pop it off. Using needle nose pliers, remove the pin holding in the float and carefully remove the float, along with the needle.
Step 3: Cleaning
Only use a carburetor specific clean as this won’t damage any components associated with the carburetor, yet clean the unit efficiently. Apply the cleaning product in a bucket or pan large enough so the product doesn’t spray on surrounding objects. I would highly recommend wearing safety glass and latex gloves. Apply the cleaner to the outside washing any dirt away, then move onto the inside and finally moving onto the passages. It is best using something to push through these passages such as fishing line. I’m using a torch tip cleaning set, but you must be extremely careful with these as they do have a slightly abrasive surface which can increase the size of the holes, especially in the brass components, therefore damaging the accuracy of the carburetor. Spray the cleaner in the intake manifold.
Step 4: Gasket Preparation
You may find some o-rings or seals have dries out over time and now is a good time to replace those by either going to a local small engine parts supplier or finding parts online. Sometimes we can salvage the old gaskets. Use a gasket scraper or razor knife on edge to remove the old gaskets, be careful not to damage the sealing surfaces. Once the gasket has been removed, use a stone to smoothen the surface removing any imperfections or corrosion. When using a stone, apply penetrating oil to the surface so the aluminum does not plug up the stone’s abrasive surface.
Step 5: Reassembly
Give the unit a final spray down and clean the adjustment needles, then allow everything to dry. Reassemble the carburetor and reinstall intake manifold, I will be using blue medium strength thread locker made by Permatex. Be sure you do install the float bowl in the correct orientation. As for the settings on the, you can set them to the previous setting before it was disassembled, but they could have been possibly wrong. A generic setting to get the engine running for the idle screw is 3/4 of a turn and for the main jet on the float bowl is 1.5 turns out. Reinstall the carburetor back onto the engine block. Again you can use the same product, blue medium strength thread locker by Permatex on the bolts.