LA145 can't start engine

[stevelee8949]

:confused2:Hi everyone, I neep help!

4 year old John Deer LA145 model,
Engine not started, so I replaced: spark plugs(two), oil filter and Oil, feul filter, air cleaner, and battery, but still engine not started...
When turn key, fan(disk shape located in the middle) rotates and trying to start sounds, but actual ENGINE not starting...
Please help, I need to cut lawn asap...
Thank you,

 

[beenthere]

:welcome:

Need a spark, some fuel, and air.

Now that you have new plugs, do you know if you have spark?

Do you know if you are getting fuel into the combustion chamber?

Likely are getting air with new air filter, and good on the new battery.

Spark will be the culprit, and not getting spark may be that one of several "safety" (and annoying) switches are not reset. Check them all...seat, neutral, mower switch off... not sure if any others are on the LA145. Maybe the manual has a list of them.

 

[stevelee8949]

:welcome:

Need a spark, some fuel, and air.

Now that you have new plugs, do you know if you have spark?

Do you know if you are getting fuel into the combustion chamber?

Likely are getting air with new air filter, and good on the new battery.

Spark will be the culprit, and not getting spark may be that one of several "safety" (and annoying) switches are not reset. Check them all...seat, neutral, mower switch off... not sure if any others are on the LA145. Maybe the manual has a list of them.

Thanks for help...
How do I know it ignites spark?
I am suspecting that fuel is not getting into the combustion chamber, what is the black 2inch dia plastic thing located between fuel filter and carbureta?
It looks like I guess maybe fuel pump, am I right?
I checked the cabureta and looks clean and all holes are open, but I cleaned anyway by cleaner spray, but still the same,
My guess is
1) no spark?
2) no fuel flows in to cabureta?
3) fuel pump gone?

I didn't make the gas tank empty last year so, 1/5 of gas has been in the tank as left over, could this clog the fuel line? how to check and verify fuel flows well from tank to cabureta?

Thanks

 

[jinman]

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.

 

[beenthere]

Spark can be tested by removing the plug, attaching it to the plug wire and resting the threads on a grounded metal part (just so you can see the plug tip. Turn the engine over and observe if there is a good spark coming at the tip. If none or just an occasional weak spark, then likely a problem.
Old fuel could also be a problem, but the teaspoon of fuel in the carb as suggested by jinman should answer that question (and the spark question as well).

 

[jinman]

By all means, check for a spark as beenthere suggested. It's an easy check and will verify the electrical system. For more info on the needle valve check out this thread.

 

[stevelee8949]

By all means, check for a spark as beenthere suggested. It's an easy check and will verify the electrical system. For more info on the needle valve check out this thread.

Thanks Jim and Beenthere,

I have learned a lot and will learn more...I am happy to learn..

Ok, today I am going to test these two things first:

1) remove the hose( coming from the fuel pump) from Carb, and see gas comes out of hose or not, if coming out, then something wrong in CARB ( like Jim said, needle valve, etc), if gas not coming out from the detached hose, then something wrong in "from Gas Tank to fuel pump"

2) test CARB by add some gas directly into CARB.


My question is
If something wrong between Gas tank adn fuel pump, then what should I do?
do I have to replace fuel pump? or do I need to replace hose from gas tank to fuel pump?
Would it be possible the hose which attached to the gas tank can clogged?
IOW, left-over gas could cause any problem?
Should I empty the Gas Tank after summer?

Thanks,

 

[jinman]

Steve, I put Sta-Bil in my gasoline and leave it in the mower during the winter. I've never had a clog.

If you disconnect that hose on the outlet side of your fuel pump and turn the engine over, it should squirt out fuel if the pump is working. The pump works off of crankcase pressure. It's a diaphragm pump and the changing crankcase pressure works the rubber diaphragm. Unless the diaphragm is damaged internally, it should work fine. I would suspect your fuel filter being clogged before the fuel line from the tank. I would bet that you'll see plenty of fuel once you remove the outlet side hose of the pump. I know I did on my despite the carb float valve being stuck. The fuel pressure from the pump was not enough to unstick the needle valve. It took low pressure from an air compressor to unseat my valve, and then it would work fine for a few times mowing before it would stick again. There's a little rubber tip on the needle valve that seems to deteriorate and stick inside the orifice.

 

[stevelee8949]

Steve, I put Sta-Bil in my gasoline and leave it in the mower during the winter. I've never had a clog.

If you disconnect that hose on the outlet side of your fuel pump and turn the engine over, it should squirt out fuel if the pump is working. The pump works off of crankcase pressure. It's a diaphragm pump and the changing crankcase pressure works the rubber diaphragm. Unless the diaphragm is damaged internally, it should work fine. I would suspect your fuel filter being clogged before the fuel line from the tank. I would bet that you'll see plenty of fuel once you remove the outlet side hose of the pump. I know I did on my despite the carb float valve being stuck. The fuel pressure from the pump was not enough to unstick the needle valve. It took low pressure from an air compressor to unseat my valve, and then it would work fine for a few times mowing before it would stick again. There's a little rubber tip on the needle valve that seems to deteriorate and stick inside the orifice.

I will test this afternoon around 5pm, and will report what I seen, and will ask help again if needed, thanks...

 

[Egon]

A simple spark tester.

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