Small Engines (Lawn Mowers, etc.): primer bulb will not expand, carburetor body, craftsman model


Question
QUESTION: craftsman model number 358.797170 i am unable to have the
primer bulb expand after compressing it. I removed the carb
cleaned replaced and still difficult to expand the bulb. If i
loosen the top screws it will. Does the diaphragm need to be
replaced? this happened after gas ran out

ANSWER: Hello Sam:

>>To View a Breakdown of this Unit Go to this Site Addy, http://www.searspartsdirect.com/partsdirect/index.action?sid=PSHx20080114x00001 and Enter the Model Numbers 358.797170 and Select Model Search. Now Select Go. From this Page you can View Diagrams and Parts Lists.
>>Select the Picture with the Fuel Tank.
>>For a Breakdown of the Carburetor,
>>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.
>>A Restricted Fuel Filter, a Restricted Passage inside the Carburetor or the Carburetor Metering Needle Valve Stuck, are the Common Causes for this Problem.
>>Replace the Fuel Filter inside the Tank.
>>Disassemble the Carburetor and Blow Out the Passages with Compressed Air.
>>IF the Carburetor has Never been Soaked and Cleaned, then I Suggest
>>Soaking and Cleaning the Carburetor.
>>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. Have a Happy Holiday Season 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 Now Accepted Anytime. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John


---------- FOLLOW-UP ----------

QUESTION: Hi John thanks for the info. The OEM on the carb is ZAMA and
the model is C1Q-W11. Hope this is the info you were looking
for to help with the breakdown of the carb. Happy Thanksgiving
to you and your family Sam

Answer
Hello Again Sam:

>>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.
>>As Always, 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. Have a Happy Holiday Season 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 Now Accepted Anytime. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John