Small Engines (Lawn Mowers, etc.): Tecumseh valves, trouble shooting guide, cam shaft

Question
I have a L head 10 Hp Tecumseh TVXL220.  I just overhauled the engine but it won't start. Good spark and fuel. The engine will not pop at all.  Timing is fixed by the location of the CDI coil so must be correct. But seems that the compression release releases too much.  Feeling at the spark plug hole, there is also a lot of suction.  I trimmed the valve stems to 0.008 to 0.012" as the manual said.  I notice that right at the top of the stroke, the Exh valve opens slightly.  I did not touch the spring assy at the end of the cam shaft.  Please advise.  Thanks,   Hal

Answer
Hello Hal:

Sorry for the Delay. This Question was Located in the Question Pool and I can Only Answer Questions from the Question Pool when I am Not Answering Questions here or at the Other Site I Answer Questions at. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.outdoordistributors.com/ and Select the T. Then Select Tecumseh. Then Select Don't have Part Numbers. Then Enter the Model Numbers. Then Select your Model and Download the File for Online Viewing. Since this is a Tecumseh Engine, I have a PDF Site Addy that May Assist you Also. http://www.tecumsehpower.com/CustomerService/BSI.pdf  .  This Site Addy; http://www.outdoordistributors.com/Tecumseh/tmain.html has a Link to a PDF Trouble-Shooting Guide. Simple Select the Free PDF Download for the Tecumseh Trouble-Shooting Guide. The Exhaust Valve should Open Slightly as you Described. This is the Easy Start Compression Release Working. Did you De-Glaze the Cylinder when you had the Piston Out? What was the Compression Rings End Gap? Was it Less than .035in? Did you Lap the Valves?  Will the Engine Try to Start if you; The Following is a Basic Instruction for Checking the Carburetor. Any Input is Appreciated. **First, Pour a Small Amount of Fuel Mix Into the Carburetor Throat while Holding the Throttle at Full. Still Holding the Throttle at Full, Try to Start the Engine. If the Engine Starts and Quits, then 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, Float Pin, Float 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.** You can Try Pouring a Small Amount (approximately 1/2 to 1oz) of Crankcase Oil Into the Cylinder and then Try Starting it. Sometimes on a Rebuilt Engine, the Rings Do Not Seal Properly with the Cylinder Wall and this Causes Compression Loss. The Crankcase Oil Makes a Seal between the Rings and the Cylinder Wall and Burns Off Shortly After the Engine Starts. The Oil Assists in Increasing the Compression Long Enough for the Rings to Start Seating to the De-Glazed Cylinder Wall and Sealing so the Engine will have Enough Compression to Start Normally. This is Usually Required for the Initial Start Up. 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