Small Engines (Lawn Mowers, etc.): Honda GX120-QXS2 wont keep running, twin cylinder engines, honda gx120

Question

serial # I have a paint sprayer with this engine.  It will "start" briefly and then shuts down.  It will continue running if I keep spraying carb cleaner in the air intake.  I installed a new carb, air filter, plug and oil, but to no avial.  I checked the fuel line and filter in the tank and the fuel flows freely.  I'm now at a loss.  Any help would be much appreciated.

Answer
Hello Mark:

On this Model Engine there can be Several Causes for the Problem you Described. You can View a Breakdown/IPL of the Mower/Engine at this Site Addy, http://hayward.arinet.com/scripts/EmpartISAPI.dll?MF&app=ASP&lang=EN&TF=Mainfram... and Select the Catalog American Honda. Select the Engine File. Now Scroll to your Model Engine and Select it. 1- the Valve Clearance Require Setting. The Following is a Basic File I made for Setting the Valve Clearances. Any Input is Appreciated. **I Do Not Use the Setting Called for by the OEMs. I have Found that the Following Works Best. Remove the Valve Cover (on the Dead Cylinder for Twin Cylinder Engines). Set the Cylinder you are Setting the Valves on to Top Dead Center on the Compression Stroke When Setting the Valve Clearance. Now Loosen the Valve Adjuster Locks and Using a Blade Style Feeler Gauge, Set the Intake Valve Clearance to .005in -.007in and the Exhaust to .007in - .009in. I have had Better Performance Out of the Mowers and Less Burnt Valves Using these Settings. Be Sure the Piston is at TDC on the Compression Stroke.** If you Remove the Valve Cover and then Turn the Engine by Hand, you can Watch the Intake Valve Movement. When the Intake Valve Closes, the Piston will Just Starting the Compression/Power Stroke. On Some Engines you can Us a Straightened Coat Hanger and Feel the Piston. Be Careful and Dont Jam the Wire in the Cylinder. Usually the Piston will Push the Wire Out of the Spark Plug Hole with No Problems. 2- the Spring on the Compression Release has Broken and the Compression Release is Staying Engaged Constantly Causing Loss of Compression/Suction. 3- A Blown Head Gasket. If the Head Gasket Blows Between the Push Tube Galley and the Compression Chamber you can have the Problem you Described. 4- Are you Sure the Float on the New Carburetor is Floating Freely and is Not Stuck in the Up Position? If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. Have a Happy Holiday Season and May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John