QuestionQUESTION: Hello John,
I have a Craftsman 6.75HP lawn mower, Mod. no.917.377610. I believe it has a Tecumseh engine. It starts up fine when cold, but when shut off gas will leak out what appears to be the air intake for the carb ( which is horizontal) and pool in the air cleaner cavity. I removed the float bowl asmbly and checked the float and needle. It seems to be shutting the gas intake when float is raised, so I don't think it's the bowl overflowing. Is it possible that the gas is siphoning thru the main nozzle into the air intake after the mower is shut off? Have you ever seen this before? Any ideas what could cause this?
Thanks,
Joe
ANSWER: Hello Joe:
Check the Gas Tank Cap. If the Cap is Not Venting the Tank, then Pressure Builds Up and Pushes the Gas through the Carburetor Jet and Into the Carburetor Throat as you Described. Also, the Carburetor Float Needle May Not be Seating Properly and Causing this Problem. I Suggest you **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.** 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: Hi John,
Thank you for your quick response to my problem. I checked the gas tank cap as you suggested and found that there looks to be a kind of rubber baffle with foam under it on the inside of the cap, but there is no vent hole anywhere on the outside of the cap. I'm thinking of drilling a couple of small (1/8") holes in the cap to vent, and see if that takes care of the problem. What are your thoughts on that?
Thanks again,
Joe
AnswerHello Joe:
If you can Not Locate a Vent Hole in the Side or Top of the cap, then Drill a Small Hole (smallest Possible) in the Cap. A 1/8" Hole is too Large. The Smallest Drill Bit in your Bit Set will be Better. I Really Suggest you Purchase a New Cap. 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
