Mower wont start.

[eng3]

I have a Toro 124k02-0110-b1 mower.
It has been working fine all season. There has been a small fuel leak which only occurs while running.
Anyways, suddenly, it wont start. When I pull, it spins, but the engine doesn't turn over and does not seem like it is trying. Plenty of fuel in the tank. It worked last week so I assume the fuel is good. I checked and changed the spark plug, I can visibly see the spark. I also changed the air filter. I removed the screw/bowl of the carburetor. There is fuel at the bottom. I can see through the hole in the screw but clean it out anyways so the hole is bigger now.

We have fuel, air, spark so I would think it should start.

I am not exactly sure which direction the fuel flows in the carburetor. If there is fuel in the bowl, does it mean there is fuel/air getting to the cylinder?

I'd appreciate any recommendations

 

[hlw49]

No not necessarily. Make sure the orifices in the bowl nut are clean and open. If they are. What can happen is the seat will move down in the well where it sets thus raising the float and shutting the flow of fuel entering the carb. bowl. If that is what has happened the toe of the float will be elevated and this shuts the fuel flow to the bowl. The float with the carb inverted with the float up the float should sit level. If that is the problem you will need a 398188 needle and set kit and 796610 bowl gasket if needed. If you have a good compressor you can blow the seat out and drop the new one in with the smooth side up and press it in with a good smooth punch. Oh yes putting a little oil on the seat before you drop it in the well will help it press in easier.

 

[eng3]

I see, I'll check the seat/needle.
the bowl and nut are very easy to get off so I did that first.

 

[Richard Milhous]

We have fuel, air, spark so I would think it should start.

I am not exactly sure which direction the fuel flows in the carburetor. If there is fuel in the bowl, does it mean there is fuel/air getting to the cylinder?

No. Fuel has to get from the bowl to the cylinder, and there's many a slip 'twixt cup and lip.

Clogged passages/jets.
Vacuum leak.
Intake valve seat loose.
Intake valve not opening enough.
Valve timing off.
Choke open.
Throttle not open.

It's not just fuel/air/spark. Fuel and air have to be in the right proportion, which varies with engine temperature and load. You need vacuum and compression, valves have to seal, and everything has to be timed right. The spark has to be strong enough to jump the resistance of compressed air, which is several times stronger than when you ground the plug to the block in open air. And of course, even if you get a little cough, the engine won't start if it's under load.

 

[hlw49]

No not necessarily. Make sure the orifices in the bowl nut are clean and open. If they are. What can happen is the seat will move down in the well where it sets thus raising the float and shutting the flow of fuel entering the carb. bowl. If that is what has happened the toe of the float will be elevated and this shuts the fuel flow to the bowl. The float with the carb inverted with the float up the float should sit level. If that is the problem you will need a 398188 needle and set kit and 796610 bowl gasket if needed. If you have a good compressor you can blow the seat out and drop the new one in with the smooth side up and press it in with a good smooth punch. Oh yes putting a little oil on the seat before you drop it in the well will help it press in easier.

Before you go to all the trouble of any of this spray a little gum out carb clean in the carb and see if it runs and dies. If it does them you will know it has a carb issue.

 

[eng3]

So I pulled the cover off and noticed a small rock holding the throttle (valve) partially closed. Maybe 20% closed? hard to tell, not much.
I thought maybe this was the cause so I tried starting the engine but no joy.

I wasn't sure where exactly where I should spray the carb spray to test, I just shoved it through where the air goes in as far as I could to try to get it in the engine. I did maybe a 1-2 second spray.
Pulled and it started with a puff of black smoke coming out the front (which is strange since exhaust comes out the side). To my surprise it stayed running and did not die (at least for 30sec before I gave up).

I then went ahead and started it again and mowed the law with no issue.

Still not sure exactly what the issue was/is.

 

[hlw49]

So I pulled the cover off and noticed a small rock holding the throttle (valve) partially closed. Maybe 20% closed? hard to tell, not much.
I thought maybe this was the cause so I tried starting the engine but no joy.

I wasn't sure where exactly where I should spray the carb spray to test, I just shoved it through where the air goes in as far as I could to try to get it in the engine. I did maybe a 1-2 second spray.
Pulled and it started with a puff of black smoke coming out the front (which is strange since exhaust comes out the side). To my surprise it stayed running and did not die (at least for 30sec before I gave up).

I then went ahead and started it again and mowed the law with no issue.

Still not sure exactly what the issue was/is.

Could be the primer system. with the air filter off pump the primer and look in the throat of the carb and see if you can see fuel coming out of the main nozzle. If not you may have to replace the air cleaner base part no.795259. They sometime warp and it won't pump air into the carb bowl and push the fuel out the main nozzle.

 

[eng3]

Could be the primer system. with the air filter off pump the primer and look in the throat of the carb and see if you can see fuel coming out of the main nozzle. If not you may have to replace the air cleaner base part no.795259. They sometime warp and it won't pump air into the carb bowl and push the fuel out the main nozzle.

Might be. This morning, it wouldnt start again, spraying some carb cleaner allowed it to start up.

The air cleaner base part has a metal piece blocking the hole on the side going in but I can fit the straw from the carb cleaner can down it. However I can't see inside very well. I tried looking through the gap and it doesnt looking like anything is coming out when I press the primer

 

[hlw49]

Might be. This morning, it wouldnt start again, spraying some carb cleaner allowed it to start up.

The air cleaner base part has a metal piece blocking the hole on the side going in but I can fit the straw from the carb cleaner can down it. However I can't see inside very well. I tried looking through the gap and it doesnt looking like anything is coming out when I press the primer

It Could be the primer bulb as well make sure it is not cracked. Gas won't just gush out but you should be able to see it.

 

[eng3]

It Could be the primer bulb as well make sure it is not cracked. Gas won't just gush out but you should be able to see it.

I see no cracks. I found a youtube video demonstrating it and I don't see anything coming out so I guess it is probably that.

I seem to be able to find a replacement for as cheap as $10 so it seems like a pretty simple thing to just try.