John Deere L120 over heating?

[sheetmetalbabe]

OMG
I took the shroud off and there wasn't anything under there except a little film of dirt, but I cleaned if off.
I put B&S oil in it. Called the John Deere Dealer and he said I shouldn't mix the part synthetic oil with the regular and it would get hotter but not enough to make it die.
I mowed 4 laps!! And then it died. I cooled it off with my leaf bower and mowed 2 more laps. Before it dies it starts surging A LOT.
I also noticed the air plenum extension was coming apart and the clip was barely on there. If you close the hood and look thru the louvers there are some gaps where the
extension fits around the grill on top of the fly wheel. Sounds stupid but if all the heat isn't exiting thru the louvers could that make it too hot? The air plenum extension has a small melted spot on it.
I took it off and tried to close the gap but it didn't work. JD dealer is closed and they don't have any in stock anyway. I can't find any pictures of one but I think the gap should be closed????
I did forget to loosen the gas cap, I will try to remember when I go back out, but I did blow air thru it yesterday and it is clean as a whistle.
The JD guy said maybe a coil???? Guess I will watch some youtube videos on coils and check back to see if anyone has any ideas.
Thanks for all the tips, I do appreciate you all taking the time to read this and reply!!!!!!!

 

[Carscw]

When a bad coil gets hot it grounds out and stops working.
When you cooled it off it goes back to working.

 

[sheetmetalbabe]

When a bad coil gets hot it grounds out and stops working.
When you cooled it off it goes back to working.

How bad would it be to mow with the hood off to keep it cool???
Just so the grass doesn't get any more out of control while I figure out the coil thing?

 

[SeniorCitizen]

OMG
I took the shroud off and there wasn't anything under there except a little film of dirt, but I cleaned if off.
I put B&S oil in it. Called the John Deere Dealer and he said I shouldn't mix the part synthetic oil with the regular and it would get hotter but not enough to make it die.
I mowed 4 laps!! And then it died. I cooled it off with my leaf bower and mowed 2 more laps. Before it dies it starts surging A LOT.
I also noticed the air plenum extension was coming apart and the clip was barely on there. If you close the hood and look thru the louvers there are some gaps where the
extension fits around the grill on top of the fly wheel. Sounds stupid but if all the heat isn't exiting thru the louvers could that make it too hot? The air plenum extension has a small melted spot on it.
I took it off and tried to close the gap but it didn't work. JD dealer is closed and they don't have any in stock anyway. I can't find any pictures of one but I think the gap should be closed????
I did forget to loosen the gas cap, I will try to remember when I go back out, but I did blow air thru it yesterday and it is clean as a whistle.
The JD guy said maybe a coil???? Guess I will watch some youtube videos on coils and check back to see if anyone has any ideas.
Thanks for all the tips, I do appreciate you all taking the time to read this and reply!!!!!!!

If your tractor looks similar to this one, the normal air flow for cooling is for the air to enter the louver area on both sides of the hood. Those areas are connected to the round plenum I believe you called it, tinner talk. :laughing:

From there it is drawn in by the flywheel air vanes, travels under the shroud you removed to check for mouse nest and is discharged at the front across the heads on each side. If you carefully place your hand below the heads you'll feel the discharge air. On my tractor that would be below the grill near the ends of the bumper on each side.

Note: these engines are designed to mow at full throttle RPM. Just going to the mail box like I do sometimes lower RPM is OK but under load mowing take the RPM to the top. And of course the outdoor ambient temperature makes a huge difference too being air is the little feller's only method of cooling. Mowing at 70°F as opposed to 95 makes a world of difference.

The melted spot on the extension you mention I don't know about. Maybe it was rubbing on the rotating flywheel screen for some reason.

 

[Mad Mackie]

Vapor lock?
Charging system not operating properly?

 

[sheetmetalbabe]

Tinner talk LOLOL!!!! You are right but I actually looked it up in the JD Parts Catalog so you all would know what I was talking about
I am also a commercial/industrial roofer, but that talk isn't allowed on here, aahahaha.
Yes, my John Deere looks like that, just no bumper and some peeling pain and a little rust on the deck. I bought it in 2005!
I always mow at full throttle, in case you were wondering.
I call the JD dealer so much they offered me a job :laughing: So is mowing without the hood on a really bad idea?
I don't mean to be such a girl but I thought it would stay cool that way. It has cooled off at least 10 degrees in the last hour, maybe 15. I am going to go see how many laps I can get.
I will be back......

 

[sheetmetalbabe]

When a bad coil gets hot it grounds out and stops working.
When you cooled it off it goes back to working.

That will be my next step. I already know way more about this mower than I wanted, LOL.
Thanks

 

[shiftsuper175607]

OMG
I took the shroud off and there wasn't anything under there except a little film of dirt, but I cleaned if off.
I put B&S oil in it. Called the John Deere Dealer and he said I shouldn't mix the part synthetic oil with the regular and it would get hotter but not enough to make it die.
I mowed 4 laps!! And then it died. I cooled it off with my leaf bower and mowed 2 more laps. Before it dies it starts surging A LOT.
I also noticed the air plenum extension was coming apart and the clip was barely on there. If you close the hood and look thru the louvers there are some gaps where the
extension fits around the grill on top of the fly wheel. Sounds stupid but if all the heat isn't exiting thru the louvers could that make it too hot? The air plenum extension has a small melted spot on it.
I took it off and tried to close the gap but it didn't work. JD dealer is closed and they don't have any in stock anyway. I can't find any pictures of one but I think the gap should be closed????
I did forget to loosen the gas cap, I will try to remember when I go back out, but I did blow air thru it yesterday and it is clean as a whistle.
The JD guy said maybe a coil???? Guess I will watch some youtube videos on coils and check back to see if anyone has any ideas.
Thanks for all the tips, I do appreciate you all taking the time to read this and reply!!!!!!!

Try leaving the plenum off and see if it stays cooler.

also, If the engine is running too lean it can get hot.

 

[sheetmetalbabe]

Try leaving the plenum off and see if it stays cooler.

also, If the engine is running too lean it can get hot.

That is a good idea. I was actually raising the hood while mowing to try and cool it off, 7 laps! Yes, I know each lap is shorter than the first.
The grass is wet, temp dropped and must have hit dew point, it's gonna look like crap in the morning. Oh well, at least I got 1/2 the back done.
What is too lean? The gas/air mix in the carb? How do I fix that?

 

[SeniorCitizen]

The design is to cool with outdoor ambient air rather than the flywheel air pump attempting to cool with hot air from the engine compartment. It needs the hood and the plenum.