Poulan Pro (PR173Y22RP) - Problem Starting and Running ... Potential Carb Issue

[keredklo]

Problem: Poulan Pro lawn mower will not start. Based upon my current analysis and troubleshooting, it looks to be carburetor related but have run out of next steps and would really appreciate your expertise to help direct me towards either fixing it or trashing it.

Specifications: Poulan Pro PR173Y22RP

Root Cause: The root cause is still unknown Here is a list of troubleshooting steps that I have taken to isolate the issue:

1) Took off the fuel tank and emptied out all of the old gasoline. Filled it with new gas that I use on my John Deere.
2) Validated that gas was flowing from the tank to the carb.
3) Took off the cover holding in the air filter that exposes the carb's butterfly valve. To see if the engine would fire, I put a small amount of gasoline into the butterfly and it fired out momentarily and died.
4) Took off all of the hose inputs on the carburetor and used a toothpick to try to unclog any potential blockage It didn't work.

I can see that gas is getting to carb, but it doesn't seem like it is flowing through to the butterfly valve and into the engine. My knowledge of carburetor痴 is limited and don't really want to rebuild one.

Any help or thoughts would be greatly appreciated.

Picture 1 Lawn Mower


Picture 2 Carburetor Cover


Picture 3 Carburetor

 

[EngineMan]

Have you got compression
Is there a spark
Is the spark plug wet or dry
Is the choke control working
You say that there is fuel getting to the carburetor, but have you taken it off and cleaned it out, you are looking for deposits of dirt and/or varnish, damaged seals/gaskets or vacuum leaks.

If you are sure that its fuel, look at tank, fuel line's (pipe's) carburetor and seals/gaskets between carburetor and engine in that order.

 

[Lawnranger]

Since the engine ran with a small amount of gasoline poured in the intake, that tells you that the engine has sufficient compression and spark at the right time. The only missing factor is the proper air/fuel ratio. You can also spray carburetor cleaner in the intake, start the engine and continue to spray short blasts of carburetor cleaner in the intake to keep the engine running for a longer period of time, for testing purposes only, to determine if the engine sounds normal. If the engine sounds normal and you don't want to rebuild the carburetor yourself, you have three choices: one, stop using the mower and junk it/sell it as is; two, buy a new carburetor and replace the existing carburetor; three, pay someone else to fix the carburetor.

Good luck

 

[Terrbare60]

I've come across the same, or similar situation, the mower started and ran a short time, about 50 ft of mowing, then shut down, needless to say, it didn't start back up, wasn't lacking fuel, but after about 15-20 minutes of cool down, it started back up, but again, didn't run long. Before all this happened, I went through the carb, cleaned it all out, and added fresh gasoline. My next choice of repair to look into is possibly electrical, could it be the coil getting hot, causing this situation?
Years ago, I had the same thing happen to some outboard motors I've worked on.