LA145 can't start engine

jhonb · Apr 3, 2012

Egon said:
A simple spark tester.

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My older brothers used me as their spark tester when we were kids. They would tell me to hold the spark plug wire and watch my reaction when they pulled the cord....

jinman · Apr 3, 2012

jhonb said:
My older brothers used me as their spark tester when we were kids. They would tell me to hold the spark plug wire and watch my reaction when they pulled the cord....

Well. . . that explains a lot of things, doesn't it?:confused2::laughing:

stevelee8949 · Apr 3, 2012

not tested yet but I recalled one thing from my memory of yesterday' work on LA145.
Very small gas came out from hose when I removed the fuel filter, and then no more gas flows out from the hose.
so, I think now that something maybe clogged between gas tank and before fuel filter, in other words, hose is maybe blocked somewhere inside of tube or the tank outlet or tank...
Right?

stevelee8949 · Apr 3, 2012

Hello,

BTW,
What's normal life time for the fuel pump? 5yrs? or 10yrs? or more than that?

jinman · Apr 3, 2012

stevelee8949 said:
not tested yet but I recalled one thing from my memory of yesterday' work on LA145.
Very small gas came out from hose when I removed the fuel filter, and then no more gas flows out from the hose.
so, I think now that something maybe clogged between gas tank and before fuel filter, in other words, hose is maybe blocked somewhere inside of tube or the tank outlet or tank...
Right?

Remove the hose going to the filter. Open the gas cap and blow into the tank. You should see gas freely flow out the hose if there are no clogs. My guess is the filter is the source of most clogs.

I don't think there is MTBF info on the fuel pump. I'd say they could be expected to last the life of the mower unless something abnormal occurs. I also believe they can be purchased online as a generic B&S or Kohler fuel pump since they are used on both brands of engines.

stevelee8949 · Apr 3, 2012

Here is the report so far,

1) tested and runs OK when I add GAS directly into Garb.

2) tested, plug out the hose from Garb, to see if any gas comes out from hose ==> no gas comes out when I turn starter ==> so, I changed new fuel pump ==> then gas comes out from the hose from puel pump==> now fuel pump is OK, then connect the hose to carb, and then engine not started.
3) Tested, hose from gas tank to fuel filter, and it's OK- I checked blow first and suck it in, then gas comes out from Gas tank thorough the hose.

now I have no idea where to look at??

any help PLEASE, thanks much,

stevelee8949 · Apr 3, 2012

jinman said:
My guess is your float chamber needle valve is stuck. It's a common problem with these mowers. You can use low pressure air (30 psi) into the fuel hose where it goes into the carb to unstick the needle valve. The full solution is to get a replacement brass needle valve to replace the plastic one that came with the Briggs & Stratton engine from the factory.

You can prove that it's a fuel problem by removing the air cleaner and pouring a tablespoonful of fuel into the intake throat of the carb. Then, try to start the engine. If the engine will try to start or starts for a few seconds, you can be pretty sure the stuck needle valve is the problem. There's also a fuel cutoff solenoid on the bottom of the carb, but these rarely malfunction.

BTW: Your John Deere dealer should be aware of this problem (lawn mower repair shop). It's an easy repair if you know what you are doing.

I guess you hit the nail!
According to my various test, I suspect the plastic needle valve ( actually fuel pump too, but already replaced it) stuck.
Where can I buy brass needle valve for LA145?
part#?

Thanks,

jinman · Apr 3, 2012

You still need to pressurize the hose to the carb with around 30 psi. You can't do that by blowing into the hose, you'll have to use a compressor. Also, when you turn the key on, does the fuel solenoid on the bottom of the carb energize with a click? Check to make sure that is also working.

EDIT: For details of carb disassy, follow this link. I thought the problem was trash and disassembled the carb, but the problem came back and I finally found it was the needle valve exactly as justwork suggested.

jinman · Apr 3, 2012

stevelee8949 said:
Where can I buy brass needle valve for LA145?
part#?

Thanks,

I think you can get it from your JD dealer, but I ordered mine directly from Briggs & Stratton online parts sales.

stevelee8949 · Apr 3, 2012

jinman said:
I think you can get it from your JD dealer, but I ordered mine directly from Briggs & Stratton online parts sales.

Jim,

Thanks I will check it out tomorrow,
BTW,
I replaced new 12V battery two days ago and I tried to start a couple of times, but failed, so I am wondering my new battery could be drown out?
like turning the starter key and holding it more than 10 seconds or 20 seconds a couple of times, then battery can be dead?
So, I should not keep holding key more than a couple of seconds?
Thanks,