Small Engines (Lawn Mowers, etc.): overhead valve gap for honda lawnmower, blown head gasket, honda lawnmower


Question
I have a honda lawnmower that runs great but blows out a lot of white smoke out of exhaust.I was wanting to set the gap on the valves to see if this might be the problem. Do you know what the gap is for a model HR-214-FG FOR BOTH THE INTAKE AND EXHAUST. THANK YOU FOR ANY HELP.

Answer
Hello Jim:

White Smoke from the Exhaust is Usually a Sign of; A- Gas in the Crnakcase Oil. The Following is an Instruction File I Made for this Repair. Any Input Concerning the File is Appreciated. Depending on the Engine Model, Usually the Gas in the Crankcase Oil or White Smoke is Caused by the Carburetor Float Needle Valve Not Seating Properly and Allowing the Gas to Flood the Carburetor and Engine. Then the Gas Seeps by the Rings and Enters the Crankcase and Contaminates the Crankcase Oil, a Bad Diaphragm in the Fuel Pump, a Blown Head Gasket between the Cylinder and Push Tube Galley, the Crankcase Vent Stuck/Frozen/Broken or the Carburetor Flooding the Engine. 1- Clean the Carburetor and Replace the Float Needle Valve (and Seat if this Model has One). A-  **Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl (if Applicable), Float Pin (if Applicable), Float (if Applicable)  and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air. Install New Parts if Required.** If the Carburetor Float Needle is Good, then; 2- Block the Outlet Port and Pull a Vacuum on the Fuel Pump. If it Holds Vacuum, then it is Good. If Not, then the Diaphragm is Busted and the Pump Requires Replacing.  If the Fuel Pump is Good, then Check the Crankcase Oil for Gas Contamination. If the Crankcase Oil is Contaminated, then Drain and Refill the Crankcase Oil with Fresh Oil. 3- **If the Mower has a Manual Gas Shut Off Valve:  Check the Manual Cut Off Valve and Make Sure it is Cutting Off the Gas Flow to the Carburetor. A- If Not Stopping the Gas Flow, then Replace the Valve. B- If the Mower Does Not have a Manual Cut Off Valve: Install a Manual Cut Off Valve and Turn Off the Gas Flow when the Engine is Not in Use.** 4- If the Valve is Good or has Been Installed, then Remove the Cylinder Head. On the OHV Engines the Head gasket will Blow Between the Cylinder and the Push Tube Galley. This Allow Oil to be Sucked Into the Cylinder from the Crankcase and the Extra Oil is Just Enough to Cause the White Smoke. 5- Check the Crankcase Breather and Make Sure it is Clean and Operating Properly. 6- If the Crankcase Breather Sticks, then Oil is Pulled from the Crankcase into the Carburetor Throat and this Causes the White Smoke. 7- If the Crankcase Oil is Good, then Check the Gas Tank Cap and Ensure it is Venting the Tank. 8- Some of these Mowers have a Pickup Tube. Remove the Pickup Tube and Ensure the Tube Screen/Filter is Clean and the Tank Does Not have Trash in it. B- A Blown Head Gasket between the Compression Chamber and the Push Tube Galley. Replace the Head Gasket. C-  Setting the Valve Clearance: 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 Set the Intake Valve Clearance to .XXXin -.XXXin and the Exhaust to .XXXin - .XXXin. 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.** 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. Honda List Several Engines for this Model Mower. You can Locate the Valve CLearances at this Site Addy; http://www.johnfvining.com/engine_specs/honda_valve_gaps.asp . 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. May the All Mighty Bless You and Yours. 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. Ratings and Comments are Greatly Appreciated. Thanks.

Respectfully

John