QuestionQUESTION: After started, runs fine for about one minute then stalls. trouble getting re-started. Once it does re-start gas starts running out from somewhere. It has a walbro carb on it # HDC 27
ANSWER: Hello Brain:
>>This Problem can be caused by the Carburetor Metering Valve Sticking, a Restricted Muffler/Ehaust Port or a Damaged Cylinder/Jug and Rings.
>>The Following is a Basic Instruction File for Doing a Diagnostic on the Engine for this Problem. Any Input is Appreciated.
>>**Remove the Muffler and Make Sure the Exhaust Port is Clear.
>>If it is, then Try to Start the engine with the Muffler Off.
>>If it Starts and Runs Properly, then Clean the Spark Arrestor Screen in the Muffler or Replace the Muffler if Required. Some Mufflers will Split apart for Cleaning of the Screen and Some are Screwed/Bolted to the Outside and on Others the Muffler has to be Replaced.
>>Look Inside the Exhaust Port and Examine the Cylinder/Jug and Piston.
>>If the Cylinder and Piston Look Smooth as Glass, then the Cylinder/Jug and Piston have Not been Damaged Due to Improper Oil in Gas Mixture.
>>If the Cylinder/Jug or Piston have Scratches or Gouges, then
>>The Engine is Shot and a New Unit is Required.
>>The Equipment Manufactured Today is Designed to be Thrown Away and a New Unit Purchased Due to the Price of Replacement Parts and Labor are Usually More than Half to Three Quarters of the Cost of a New Unit.
>>The Following is a Basic File I Made for Cleaning Carburetors on Chainsaws, Trimmers, Hand Held Bklowers and Other Equipment of the Like. An Illustrated Parts Breakdown will Assist you in the Disassembly and Assembly of the Carburetor. Any Input is Appreciated. Even though the Carburetor Looks Clean, the Internal Passages May be Restricted with Varnish that Gas Causes to Build Up over Time.
>>Spray Cleaners Remove this Varnish in Layers, so Soaking is the Only Sure Way to Remove ALL this Varnish.
>>I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning.
>>Remove Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed.
>>If you are Able to Remove and Disassemble the Carburetor and Keep the Gaskets Intact, then Usually these Gaskets can be Reused. The Only Parts you May Need to Replace are the Needle Valve and Metering Pump Diaphram.
>>The Metering Pump Diaphram is Under the Carburetor Plate with 4 Small Screws in it.
>>The Dowl on the Diaphram should Just Touch the Metering Jet Actuator Arm.
>>The Actuator Arm is Adjusted by Carefully Bending the Actuator Arm Up or Down to get the Correct Clearance.
>>If you Order a Kit, then Replace All the Old Components with the New Ones in the Kit even if the Old Parts Look Good.
>>Once Disassembled, 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.
>>***(Do Not Use High Pressure Air for the Zama Carburetors, they have Check Valves for the Primer and these are Usually Blown Out of the Carburetor if Not Careful. Allow the Zama Carburetor to Set on a Drip Pan and Dry)***.
>>****All the Carburetor Adjustments are the Same for Lawn Mower and Trimmers.
>>If the Main Air and Idle Air Mixture Screws are Side by Side on the Side of the Carburetor, then the Idle Air is Nearest the Engine.
>>****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 have Questions, Please Ask. The links above Provide Good Directions on Cleaning the Carburetor. Make sure you use an Compressed Air to Blow through all the Carburetor Passages to make sure they are Clear.
>>1- http://www.repairfaq.org/samnew/lmfaq/lmclctc.htm
>>2- http://www.cpdonline.com/692509.pdf .
>>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. I Hope you Had a Happy Holiday and May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 3 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. Follow Up Questions are Received Anytime. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Hello John. Well I disassembled the carb, cleaned it, and put it back together with a new carb kit.It started and I adjusted it while running and it ran great.Then died. I'm thinking maybe a filter.I will get one. I noticed though that on the gas tank there are two holes. One with the fuel line that goes to the carb. And then there is another one. Is that a vent hole? When I hold the saw up on an angle gas runs out. Is there supposed to be a check valve in it?
AnswerHello Again Brian:
>>There should be a Return Line from the Carburetor to the Tank.
>>That is What the Second Hole in the Tank is for, the Fuel Return Line from the Carburetor.
>>As Always, If you Hit a Snag or this Does Not Correct the Problem, I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 3 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. Follow Up Questions are Received Anytime. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
