QuestionQUESTION: I have a 2 year old Troy-Bilt 2-cycle blower (TB320BV, 41AS320G711) that suddenly started leaking gas through the carburetor. I took the carburetor off, opened it up (including the needle valve),blew it out with compressed air, put it back on, it still leaked. I did this 4 more times, it still leaks. I bought a new carburetor, put that on, it still leaks. It seems to me that there is a diaphragm that is supposed to retract to close the needle valve when the engine stops that may be the problem. When I blow air back and forth across it, it seems to start/stop the gas flow. Is this the problem? Is this sticking somehow (even on the new carburetor)? Is there some kind of defect with this carburetor? How do I fix?
Jeff in Virginia
ANSWER: Hello Jeff:
Check the Gas Tank Cap. If the Cap is Not Venting the Tank Propery, then Pressure Builds in the Tank and Pushes the Needle Valve Open and Causes the Gas to Leak from the Carburetor. It is Possible, Although Rare to Purchase a Carburetor with a Bad Needle Valve. Go to this Site Addy, http://www.jackssmallengines.net/parts.asp and Select Shop Online Parts Look Up. Then Select the Model Tab and Enter the OEM (Troy Bilt)and the Model Numbers. Now Double Click on your Model in the Results Area. To Assist you Further I Require the OEM (Walbro, Zama, ect) and the Model Numbers Off the Carburetor. With these I can Locate a Breakdown of the Carburetor and Better Assist you. 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: Thanks, John.
I took the cap off, cleaned it and reinstalled. Carburetor still leaked. Then I removed the cap completely, carburetor still leaked. It is a Zama P22C 73C. While leaking, it seems to drain down to the level of the primer bulb discharge tube in the tank (about ½” above the bottom) and then stops, so I assume the primer bulb line is draining the tank into the carburetor. I have replaced the fuel line that feeds into the bottom of the carburetor. (that came with the new carburetor) Is there a check valve in the primer bulb that might be leaking?
Thanks so much for your help with this.
I bought the carburetor from Jack's.
AnswerHello Again Jeff:
You can View a Breakdown/IPL of the Carburetor and Get Technical Information on Zama Carburetors at this Site Addy; http://www.zamacarb.com/tips.html and Select the Technical Guide. There are 2 Check Valves in a Zama Carburetor Primer System. The Site Addy will be of More Assistance than I will be for this Problem. Usually a New Carburetor will Correct the Problem you Described. Since you have Installed a New Carburetor and are Still having this Problem, it May be the Check Valve in the New Carburetor was Stuck from the OEM. 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
