QuestionQUESTION: I am stumped. I am repairing an FS45 with a CQ1 Carb. Engine will not prime or run for more than a couple seconds. I have pulled the carb, soaked in carb cleaner, blown out all the passages, rebuilt with a new kit. Same problem.
I pulled it back out and have tried adjusting the needle every way imaginable. No difference except now the primer bulb is not even pushing air. Oops. Critical question... Any suggestions on how to set the needle?
Have read previous posts in which you suggest that the lines are reversed. I am pressurizing the tank as a I pump, however, I pulled the lines that go into the tank to be sure the pickup is going into the bottom of the carb. It is. No fuel is making it to the priming bulb at all.
Help!
Thanks,
John
ANSWER: Hello John:
From your Description it Sounds like the Carburetor Primer Check Valve is Stuck. 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. Thanks.
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: Hey John,
You were right. The Primer Check Valve was the culprit. I replaced it and it is running. However, it is running starved for fuel. I have to choke the carb 3/4 of the way to keep it running.
I have tried replacing the diaphragm, the needle, and tuning the idle screw. I am thinking it is a matter of adjusting the needle. What do you think?
The CArb is from a Stihl FS 45. There is no brand name on it. However, I do have the following model #
C1Q S58 050A
Thanks John!
AnswerHi John:
You May need to Set the Inlet Needle Valve Height. You can Use this Site Addy that has Technical Information on Zama Carburetor to Assist you in Setting the Inlet Needle Valve of this Carburetor; http://www.zamacarb.com/tips.html and Select the 2008 Technical Guide. If this Carburetor has Air Mixture Screws, then, 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. 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. Holding the Throttle Full Open, Start the Engine. Turn the Main Air (H) 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 (L) Mixture Screw so there is No Hesitation when 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 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
