QuestionQUESTION: I'm trying to fix a Sears 22/5 snowblower with Tecumseh engine. Engine seems to starve for fuel when loaded even after thorough carb cleaning and adjustment. It will start into a snow bank then quickly dies, backfires and quits. It is then difficult to restart. I have cleaned all carb passages, jets and openings except removing the 2 welch plugs. I also replaced the carb to head gasket. I removed the head to check for leaks or compression problems. It has compression release on valve so can't readily check compression.
ANSWER: Hello Roger:
Did you Soak the Carburetor or Manually Clean the Carburetor. A Small Engine Carburetor MUST BE SOAKED to be Properly Cleaned. 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 (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. If this Carburetor has Air Mixture Screws; Are they Correctly Set? ****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.**** Send me the Model and Type or Spec Numbers Off the Engine, Please. They are Usually Stamped Into the Blower Housing (metal engine cover) Above the Spark Plug or Muffler. With these I can Locate the Proper Manual and Better Assist you. Also, Send me the Sears Model Numbers (XXX.XXXXXX) if you can Not Locate the Engine Model Numbers, Please. Thanks.
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QUESTION: John,
I gave up on the original carburetor on this Tecumseh 5HP Snow King engine. I installed a brand new carburetor which has no mixture adjustments.(The original had high and low speed needles) Unfortunately the problem persists. Although it seems to start a bit easier now and runs unloaded at all higher throttle settings, it will not run with a load. As soon as the auger engages snow the throttle plate starts to open but the engine back fires from the muffler, blue flame is emitted from the muffler and it stalls. It also refuses to idle. If the throttle is set too low the engine just dies. Re-opening it quickly does not prevent it from stopping.
What system should I look at next?
Roger
ANSWER: Hello Again Roger:
Did you Loosen or Remove the Governor Control Arm from the Governor Shaft when you Replaced the Carburetor? If Yes, then you need to 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.** If the Governor is Not Set Properly the Carburetor Throttle will Open to Quickly and Cause the Problem you are Describing. 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
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QUESTION: I finally got to the bottom of this unusual problem. Add this to your knowledge base. It was not carburetor related at all. The exhaust valve was not closing fully. Something - perhaps the valve seat was worn such that the valve never contacted the seat.I solved the problem by grinding the compression release bump off the cam and then .015" off the valve stem. This was a crude fix but it saved an otherwise junk snowblower. it starts and runs perfectly now.
Roger
AnswerHello Again Roger:
>>Thanks. I will make sure it is Added to my Files.
>>Till Next Time. May All Your Mechanical Problems be SMALL ONES and as Always, May the All Mighty Bless You and Yours. Be Safe and Happy.
Best Wishes and Good Luck
Respectfully
jbridger (John)
