How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Curtis B. Your Own Question
Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 26739
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
30244710
Type Your Small Engine Question Here...
Curtis B. is online now
A new question is answered every 9 seconds

B+S 19.5 in a John Deere LA105 wont start. Ran fine 2 weeks

Customer Question

B+S 19.5 in a John Deere LA105 won't start. Ran fine 2 weeks ago. Not getting fuel. Took carb off and blew out everything. No gum or build up. Took off fuel line off carb (fuel gettng that far) and tried to blow through onto carb but blocked. Blew air till heard it come through carb but when fuel is hooked up still nothing, took line off again and it's blocked again. Any sugestions?
Submitted: 5 years ago.
Category: Small Engine
Expert:  Curtis B. replied 5 years ago.

curtis b :

Welcome to JUST ANSWER small engines, let me try to help you !!

PU02/PU02504________UN09DEC09.gif
Full Size Image

curtis b :

You can only have one of two problems. # 9 is the needle valve that lets fuel into the bowl. If the bowl is full of fuel it is working. If not , you need to remove it and clean the port to see if there is debris keeping fuel from the carburetor. If the bowl in full of fuel, you have an electric fuel shutoff valve, #16, in the base of the carburetor. It requires 12volts to work. It should click when the key is turned one. Best test for it would be to remove it and plug the hole and test with it out. One of these two items is the problem. Let me know. Thank you.

Customer :

I am sorry it's too late for me to go out and try it now. I posted the question at 1 PM, it's nearly 6 pm now I didn't get your responce till 4:30 so I had other things to do rather then sit infront of the computer waiting on an answer to my question.The bowl did have fuel in it when I removed it to inspect the carb.

Customer :

When you say test it with out the electric fuel shutoff removed all I need to do is plug the hole the switch goes under the bowl and try it with out it? I will try that first thing in the morning.

Customer :

I just went out and tried what you said. I removed the switch and held my finger over the hole to stop the fuel from running out and it would not start. I let the bowl drain and then plugged in the switch and it operates fine when I turn on the key. The bowl was full of fuel.

curtis b :

Those are the only two items than can keep engine from getting fuel. Have you checked to see if it will run on starting fluid? If not, you could have a valve or pushrod problem and is not sucking the fuel into the cylinder.

Customer :

I got no notice of your recent answer. yes it will run with starting fluid and gas fed directly to air intake.

curtis b :

That makes it carburetor needle valve or the electric fuel shutoff solenoid. Does the solenoid click when key is turned on?

curtis b :

These Briggs solenoids can check good, but still not open . I suspect the problem is the fuel shutoff solenoid. Be sure it has 12 volts to it when the key is on.

Customer :

I CHECKED THE SHUTOFF AND IT IS WORKING!! I CAN SEE IT MOVE WHEN I TURN ON THE KEY WHEN UNSCREWED FROM BOWL

curtis b :

If you are satisfied it is ok, that only leaves the needle valve. Here is site with dis-assembly instructions.

Customer :

I thought you said if the needle valve was plugged in some way the bowl would not be filling with fuel?

curtis b :

It can let in small amount but still not enough to keep engine running.

curtis b :

As I said earlier it has to be one of these two, needle valve or solenoid. It can not be anything else if fuel is not getting to the engine.

Customer :

trying to find the carb for this mower on the link you gave me

Customer :

If I remove the shutoff solenoid with the bowl empty from checking last night, how much fuel should come out when I try to start the engine. What is too small an amount for engine to run on? I thought that might be a way to check the needle valve.

Customer :

It was none of the things you mentioned. I took out the shutoff valve and drained about a quart of gas out. I noticed it was cloudy which means water. I looked in the tank and didn't see any clouded fuel so I kept it flowing out the shutoff hole and it started to fire so I put the solenoid back in and it fired right up.

curtis b :

So no fuel was not the problem, It is hard to diagnosis when there are out side issues that we can't control. Glad you figured it out.

Customer :

Thanks for your help, But to be honest I don't think your sugestions helped that much. I am not upset but I don't think it was worth paying for.