QuestionI replaced a primerbulb on a Zama C1U-W7 carb, and had problems starting it afterward. I disassembled and cleaned carb. I removed needle valve (single needle carb), but did not count the number of turns before removing it. I still had problems after assembly. The plug is wet, and I have spark, primerbulb works. What would be a good starting point (turns)for the needle valve to be backed out?
AnswerHello Will:
>>The Following is the Instruction File for Setting the Air Mixture Screws. Any Input is Appreciated. The Procedure is the Same for 1 or 2 Mixture Screws, Just Use the Instruction File and Skip Over the Section with the Missing Mixture Screw ( Usually the H Mixture Screw).
>>Now Setting the Air Mixture Screws:
>>****Turn the Idle Air (L) and Main Air (H) Mixture Screws In Until SNUG **Do Not Jam** Then Reverse Both Screws 1 1/2 Turns. Set the Throttle Full Open, Start the Engine.
>>Turn the Main Air (H) Mixture Screw Clockwise Until Proper Revs are Obtained. **Carefully Use your Finger and Move the Governor Arm to Rev the Engine (on Chainsaws and Trimmers Use the Trigger to Rev the Engine) Until you Reach Max RPMs (on Chainsaws and Trimmers, the RPMs are Not Set to MAX. Set to Max and then Reverse the Setting Screw 1/4 or 1/2 Turn. If the H Mixture Screw is Set too High; the Engine will be Starved for the Oil in the Gas and Damage the Piston and Jug/Cylinder) and the Engine is Running Proper at Full Throttle Up a Grade and for Chainsaws and Trimmers they Do Not Bog Down Under a Load. 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 (L) Mixture Screw so there is No Hesitation when Rapidly Throttling from Idle to Full Throttle. Reset the Engine Idle if Required.****
>>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.
>>Have a Happy Holiday Weekend 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 Recieved Anytime. Comments and Ratings are
Greatly Appreciated. Thanks.
Respectfully
John
>>Hello Again Will:
>>I Just saw you Comments and Rantings and wanted to Answer your Question.
>>Turning the Mixture Screws CW will Restrict the Amount of Fuel Mixture that is Entering the Carburetor Intake.
>>Turning CCW Increases the Fuel to the Carburetor Intake.
>>Thanks for the Comments and Ratings.
>>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. 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
