Small Engines (Lawn Mowers, etc.): STHAL .025 Will not crank, carburetor body, adjustment screws

Question
Saw will not crank after 3 days prior crnking and running great..

The engine  seems to be flooding from looking at spark plug (wet)..Change plug,,Has spark as determine by holdin ghe lead in hand ang pulling the rope (lightly)...The compression seems to be ok judging from the snapping of the crank as you pulling i..It is acting as though it is not getting ignintion because the engine will load up and it gets hard to pull on the rope (flooding)  GAs mixture is fresh..  Tried readjusing mixture screws from 1 turn out etc...

Since it seems to be getting sprakk and fuel but mabe too much fuel, Do I neet to think about a carb rebuid?

Answer
Hello Bobby:

From your Description there can be Several Causes for this Problem. The Following is the Possible Causes in the Order they Should be Checked. 1- Remove the Muffler and Inspect the Exhaust Port for Carbon Blocking the Exhaust Port. Check the Muffler and Spark Arrestor Screen (in the muffler) for Blockage Also. 2-  Now Setting the Air Mixture Screws:  ****Turn the Idle Air and Main Air Mixture Screws In Until SNUG **Do Not Jam** Then Reverse Both Screws 1 1/2 Turns. Holding the Throttle Full Open, Start the Engine. Turn the Main Air Mixture Screw Clockwise Until Proper Revs are Obtained. Occasionally you May have to Turn this Counter Clockwise to Achieve the Proper Revs. Now Allow the Engine to Idle. Set the Engine Idle Screw (Not Idle Air) so the Engine will Stay Running if Required. Now Set the Idle Air Mixture Screw so there is No Hesitation when Throttling from Idle to Full Throttle. Reset the Engine Idle if Required.**** 3-  **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.** 4-  Remove the Cover that Houses the Starter Assembly. Use a Bolt the Same Diameter and Threads as the Spark Plug and About 3" Long. Thread the Bolt into the Spark Plug Hole Until it Engages the Piston. Slowly Tighten the Bolt Until you have Locked the Piston and it Does Not Move. **BE CAREFUL  A LOT OF TORQUE IS NOT REQUIRED PISTON DAMAGE CAN OCCUR IF TO MUCH TORQUE IS USED ON THE STOP BOLT** Now **Remove the Flywheel Nut. Use a 3 Jaw Puller and Attach the Puller to the Flywheel. Look for a Puller with Flat Jaws. These Slide Under the Flywheel and Allow for Easier Removal. Tighten the Puller and then Hit the Puller with a Hammer. Tighten and Hit Again Until the Flywheel is Loose and Can be Removed from the Crankshaft. Note the Key that Aligns the Flywheel to the Crankshaft. This Key is Most Likely Sheared or Bent and Causing the Plug to Fire Slightly Out of Time and Causing a Compression Lock. There is Not Enough Compression to Kick Back But Enough to Cause the Engine to Seem to Have High Compression.**  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. Thanks.

Respectfully

John