QuestionQUESTION: HELLO JOHN, MY YARD MACHINE TRACTOR WITH 18.5 HP. BRIGGS...42A707...1238...MADE IN 1997, WILL ONLY RUN ON GAS PRIMES THROUGH THE CARB! I DID A COUPLE OF CHECKS, WHEN CRANKING FUEL SPURTS OUT OF THE BOWL DRAIN HOLE. ALSO, SPRAYED WITH STRAW GUMOUT CARB CLEANER THROUGH THE MAIN JET, AND NOTED FUEL TRICKLING OUT OF THE MAIN NOZZLE.
PLEASE ADVISE, AS TO WHAT THE PROBLEM IS AND A FIX TO THE PROBLEM. THANK - YOU, JIM
ANSWER: Hello James:
From your Description, I Suggest you First 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. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model (5 or 6 Digits) and Type Numbers (first 4 digits Only). Example: XXXXXX-XXXX. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. 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: RESPECTFULLY JOHN, YOUR ANSWER DOES NOT PIN POINT THE PROBLEM. CAN YOU FORWARD A DETAILED DIAGRAM OF MY CARB, SHOWING THE ORIFICES, AND PASSAGE WAYS THROUGH OUT THE CARB ? I BELIEVE THE PROBLEM MAY BE IN THE PASSAGE WAY THAT FEEDS THE MAIN JET ! BRIGGS PICTURES ARE TO VAGUE, NOT SHOWING ANY DETAIL. THANK-YOU, FOR YOUR ASSISTANCE, JIM
AnswerHello Again James:
The Reason for Soaking the Carburetor Overnight is Because the Internal Passages of the Carburetor can Not be Cleaned Otherwise. Usually the Passages Become Restricted with Varnish. Gas Forms this Varnish Over Time and Soaking is the Only Way to Remove it from the Internal Passages. Over the Years I have Tried Everything I Could Think of and even Suggestion from Other Mechanics and have Found the Soaking to be the Best Procedure. The Breakdown is for a Reference to See how to Disassemble and Reassemble the Carburetor. BTW, Spray Cleaners Do Not Work for Cleaning the Varnish. Small Engine Carburetor Set more than an Automotive Carburetor and therefore Require Soaking to Clean them Properly. 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
