LA145 can't start engine

[stevelee8949]

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.

What is the reason to pressurize the host to carb? to clear the small hole into carb?
I don't have 30psi air compressor, where can I get it?
Thanks,

 

[Garybake]

Because of the alcohol added to fuel these days the rubber(viton) tip on the needle valve (that stops the flow of fuel in the carb when bowl is full) swells and gets stuck in the seat after sitting hot and fuel expands in bowl. You need a little bit more than fuel pressure to unstick it so fuel can fill the carb bowl again. Maybe steal the wifes turkey baster and fill with fuel and stick it in hose to carb and squeeze-(maybe first clamp baster bulb to plastic housing.) or some other hydraulic method.
A wood dowel that slides in fuel hose. Fill hose and shove dowel down hose.
Worst case remove bowl on carb. If you need to do that post update.

PS-
Do not continue to hold the key on if nothing is happening it just heats up the wires and can cause damage. If it is cranking do not hold it more than 10 seconds at a time. Charge the battery overnight and it will recover.
Hope that helps.
Gary

 

[Garybake]

Almost forgot!!!:shocked:
Turn your key to run position not start when trying to unstick needle valve or else you are forcing against a fuel shutoff solenoid :confused2: and a mess.
Gary

 

[jinman]

Almost forgot!!!:shocked:
Turn your key to run position not start when trying to unstick needle valve or else you are forcing against a fuel shutoff solenoid :confused2: and a mess.
Gary

Gary, actually the fuel fills the bowl without going through the fuel solenoid. The solenoid sits at the bottom of the carb and opens the passage from the bowl to the uptake pipe in the carb. By shutting off fuel there, the engine will instantly die. If the fuel is cut off to the float chamber, the engine would continue to run until the float chamber is empty.

Another suggestion for air is one of those little emergency air compressors that runs off the 12 volt cigarette lighter style outlets or some jumper batteries have a built-in compressor. These can produce a lot of pressure, so don't leave it running for very long. A couple of seconds into the carb should do the job. Also, bicycle pumps are a good source of compressed air for this.

 

[stevelee8949]

Can I use the dust remover can spray type? like the one used for clean computer or office equipment? too weak?

 

[stevelee8949]

Jim,

I know you replaced the plastic needle value with the brass one from B&S parts online, but I am not sure which one do I need to order because there are many brass needle value on the website, can you please let me know which one is for LA145? thanks,

 

[stevelee8949]

for example: this web-site has around 5 different needle valve, but I don't know which one matches to LA145??

Briggs and Stratton Carburetor Parts


Thanks,

 

[jinman]

Remember, I said I ordered directly from Briggs & Stratton. Here's their website with your parts. The needle valve is item #105.

You can also order the needle valve from this source. They even show a photo of the brass needle valve and say it replaces an obsolete part (the plastic one).

Knowing your engine's model number can make searching the web for parts a breeze. It's on the engine, but here is the number: 407777-0188-B1. If you type that into Google, you'll get all kinds of folks selling parts. If you go directly to the B&S website here, you can enter the model number and find any part for that engine. B&S prices are competitive to everyone else on the web, so it's really your choice.

Now, I've given you enough info to get into all kinds of trouble. . . just like me.

BTW: I think your pressurized air from the can should work just fine. Give it a try.

 

[Garybake]

Gary, actually the fuel fills the bowl without going through the fuel solenoid. The solenoid sits at the bottom of the carb and opens the passage from the bowl to the uptake pipe in the carb. By shutting off fuel there, the engine will instantly die. If the fuel is cut off to the float chamber, the engine would continue to run until the float chamber is empty.

Thanks Jinman,
I was tired and second thinking advice after reading what a tuff time Steve was having trying to get his grass cut.:thumbsup:
Gary

 

[stevelee8949]

Remember, I said I ordered directly from Briggs & Stratton. Here's their website with your parts. The needle valve is item #105.

You can also order the needle valve from this source. They even show a photo of the brass needle valve and say it replaces an obsolete part (the plastic one).

Knowing your engine's model number can make searching the web for parts a breeze. It's on the engine, but here is the number: 407777-0188-B1. If you type that into Google, you'll get all kinds of folks selling parts. If you go directly to the B&S website here, you can enter the model number and find any part for that engine. B&S prices are competitive to everyone else on the web, so it's really your choice.

Now, I've given you enough info to get into all kinds of trouble. . . just like me.

BTW: I think your pressurized air from the can should work just fine. Give it a try.

what a day!!

first of all, thank you much Jim and Gary....

Today, I cleaned again the carb and spray wd40 on the needle valve and made gas tank empty( because some of gas was last year), and put brand new Octan93 gas, and then looked at carefully all the connection, and found out there was one mis-connection at left-hand side wire bar, so I corrected it by clicking it in the small white color plastic tabbing holder( I guess this wire opens and closed one of the plates in the chamber),
and then turn the starter, but now the battery was almost going to die ( this battery is the brand new one I bought a couple of days ago)...
and engine not started, so I move my car next to LA145 and did battery jumper and eventually engine started!!! WOW!!
so, I asked my wife to remove the jumper cable and I cut lawn this evening....

So, now my question is:

1) battery is dead?
2) why it was not working without jumper, why it worked with boost battery?
3) One and half hours running could energize the almost dead battery?

Thanks,