QuestionQUESTION: I have a Scag 48" hydro walkbehind with a 17 hp Kawasaki on it the mower is only two years old and last year it quit running and a dealer rebuilt the carb and told me it was not under warranty but now it is surging real bad again even after it runs for about an hour the surge is still there mainly on lower rpm
ANSWER: Hello Michael:
The Air Mixture Screws (Depending on the Model) Require Setting. Also, Check on the Warranty. Most Engine Warrantys are for 2 Years for Homeowners. and you Stated the Engine was 2 Years Old Now, so the Engine would have Been Only a Year Old when the Carburetor was Rebuilt by the Dealer. The Mower Warranty is Seperate from the Engine Warranty. 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.**** 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
---------- FOLLOW-UP ----------
QUESTION: Ok the only think is there is only one mixture screw on this engine unless there is one that I am not seeing.
AnswerHello Again Michael:
The 1 Air Mixture Screw is the Idle Air Screw. It is Set According to the Instructions for the Idle Air Screw in my Previous E-Mail. If Setting the Idle Air Screw Does Not Stop the Surge, then, 1- the Carburetor Needs to be Soaked and Cleaned Again. **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.** 2- the Governor Require Resetting. If you Removed the Governor Arm to Remove the Carburetor, then Reset the Governor. **To Reset the Governor; Loosen the Governor Arm Bolt and Turn the Governor Shaft Clockwise Until it Stops. Using the Governor Arm Hold the Carburetor to Full Throttle. Now with the Shaft Full Clockwise and the Governor Arm and Carburetor Held at Full Throttle, Tighten the Governor Arm Bolt. If the Engine Still Runs Full Throttle, then Reverse the Rotation of the Governor Shaft, but Still Hold the Carburetor at Full Throttle with the Governor Arm. If it Still Runs at Full Throttle, then Check the Internal Governor.** 3- the Spark Plug is Gapped Wrong. **Depending on the Model Engine, then Plug Gap is Either .024in, .028in, .030in, or .040in. 4- there is a Leak in the Intake Manifold or Intake Gasket.** 5- the Valves Require Resetting. ** For this I Require the Engine Model Numbers. 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
