John Deere JS38 push mower

[dannac]

UPDATE : 1 hour 45 min later

2nd pull it started .... let it run for 15 sec and I shut it down ... did not see smoke

Tried to start it again ... 3 pulls and nothing

 

[Rivets]

Ok, now we know that you have a fuel problem. If it came to me this is what I would do.
1. Remove the carb and disassemble it.
2. Give the carb a very good cleaning.
3. Purchase a new float needle, seat, float and carb bowl gasket.
4. Reassemble carb using new parts. Pay very close attention to float height, either level or slightly lower on the side opposite the float pin.
5. Install carb and test.

Read my signature.

 

[dannac]

Ok, now we know that you have a fuel problem. If it came to me this is what I would do.
1. Remove the carb and disassemble it.
2. Give the carb a very good cleaning.
3. Purchase a new float needle, seat, float and carb bowl gasket.
4. Reassemble carb using new parts. Pay very close attention to float height, either level or slightly lower on the side opposite the float pin.
5. Install carb and test.

Read my signature.

Did you see post #50 ... as you made no remark about the smoke coming out of engine ?

 

[woodstover]

UPDATE : 1 hour 45 min later

2nd pull it started .... let it run for 15 sec and I shut it down ... did not see smoke

Tried to start it again ... 3 pulls and nothing

Have you checked that you have good fuel delivery from the tank? Pull the fuel line off at the carburetor and make sure fuel is coming out of the hose at a good rate.
Follow Rivets instructions and rebuild the carb if you have good fuel flow from the tank, otherwise, remedy the restriction in the fuel flow first.

 

[Rivets]

Yes I can read and I saw it, but you are trying to go a different direction again. I’m not worried about smoke, but if you want to go that direction I’ll get out of this thread.

 

[dannac]

Yes I can read and I saw it, but you are trying to go a different direction again. I’m not worried about smoke, but if you want to go that direction I’ll get out of this thread.

geez Rivets ... just asking a simple question.

Smoke coming out the top of the motor seemed kinda relevant to me ... guess not.

 

[Rivets]

Good Luck Sir. I’m now getting out of this thread, as I‘m just a 70+ year old retired teacher and I know when a student beats me. You might be right, that smoke might be relevant if we were looking for an oil leak.

 

[Oddjob]

UPDATE : 1 hour 45 min later

2nd pull it started .... let it run for 15 sec and I shut it down ... did not see smoke

Tried to start it again ... 3 pulls and nothing

You have a fuel problem. Cleaning the carb is never a bad idea but after reading from your original post, I see that the trouble began with restarting after shutting down a warmed up engine. I looked up the parts diagram for your JD js38 mower and saw that you have a thermostatically controlled choke. The engine starts with an assist from some carb spray but won’t restart. My guess, and I do mean guess, is that your choke is wide open. The carb cleaner is a good substitute for a closed choke, it acts like a primer. The thermostat switch is supposed to close the choke after you shut down, but it is sticking open. I have had this experience with these Briggs thermostatic chokes. I try exercising the thermostatic switch by hand until it springs back on its own. If it doesn’t spring back, buy another thermostat. You can see a good video on this switch and how to fix or replace it by googling Taryl Fixes All along with “autochoke”. I don’t know what the smoke was about. If it is gray/black then likely burning oil. A little oil smoke on startup is not usually a problem.

 

[dannac]

Good Luck Sir. I’m now getting out of this thread, as I‘m just a 70+ year old retired teacher and I know when a student beats me. You might be right, that smoke might be relevant if we were looking for an oil leak.

Never meant any disrespect to you.
Your choice to leave this thread ... can only thank you for the advice given.

 

[dannac]

You have a fuel problem. Cleaning the carb is never a bad idea but after reading from your original post, I see that the trouble began with restarting after shutting down a warmed up engine. I looked up the parts diagram for your JD js38 mower and saw that you have a thermostatically controlled choke. The engine starts with an assist from some carb spray but won’t restart. My guess, and I do mean guess, is that your choke is wide open. The carb cleaner is a good substitute for a closed choke, it acts like a primer. The thermostat switch is supposed to close the choke after you shut down, but it is sticking open. I have had this experience with these Briggs thermostatic chokes. I try exercising the thermostatic switch by hand until it springs back on its own. If it doesn’t spring back, buy another thermostat. You can see a good video on this switch and how to fix or replace it by googling Taryl Fixes All along with “autochoke”. I don’t know what the smoke was about. If it is gray/black then likely burning oil. A little oil smoke on startup is not usually a problem.

The smoke did not come when starting as it occasionally does from muffler or exhaust.
Came from top of the motor.

I removed the plastic cover as quick as I could but could not spot exactly where it came from.
And that only happened the first time I ran it today.

I will look into the autochoke you mentioned. Thanks for the info.

What I'm really not understanding is ... it started and ran as normal 3 times today, as long as the engine was cold.

How could that be a fuel problem ?