Export thread

I have a troybilt Pony riding mower that my mom bought that is having some issues.

It is overheating to the point that the muffler smokes and the spark plug wire/boot melts.

The muffler is not blowing smoke but smoking itself and just after 20-30 seconds of running. No smoke is coming out of muffler but again, the muffler is literally smoking.

It is not turning red or anything like I have heard some individuals say they experience.

The carb was changed recently due to surging and the surging stopped but now the muffler smokes and the spark plug wire melts if mower runs for longer than a minute or so.

I have checked the oil, changed it, rechecked it, changed the fuel filter, fuel lines, carb, and air filter.

I have tried adjusting carb but no luck. I checked cooling fins, no debris or blockage.

Any ideas? I'd really appreciate any help. I have really come to a halt in this fix and figured I'd reach out for some help. Thanks in advance.

put an infrared gun on the head to see how hot it is. How does it idle? Best guess is that it is jetted too lean.

sgkent said:

put an infrared gun on the head to see how hot it is. How does it idle? Best guess is that it is jetted too lean.

Click to expand...

It idles great. Since changing the carb the surging went away but it's still getting so hot the spark plug wire keeps melting.

I'll definitely try that. Do you know about how hot would be normal and excessive?

Thanks for your response and help.

Also check for loose muffler to engine connection or blown exhaust gasket. Either will the exhaust at the head run so hot even the exhaust valve seat can come out of place.

StarTech said:

Also check for loose muffler to engine connection or blown exhaust gasket. Either will the exhaust at the head run so hot even the exhaust valve seat can come out of place.

Click to expand...

Thank you, I hadn't thought of that. I forgot to mention the muffler is new and I did notice the gasket was a little old (and I didn't replace it).

I'll have to take it off and recheck it. I really appreciate your insight and help StarTech.

Kmh72412 said:

Thank you, I hadn't thought of that. I forgot to mention the muffler is new and I did notice the gasket was a little old (and I didn't replace it).

I'll have to take it off and recheck it. I really appreciate your insight and help StarTech.

Click to expand...

A new muffler will smoke until the paint anticorrosive coating burns off. And the exhaust gasket could be leaking blowing hot exhaust in the spark plug boot.

ILENGINE said:

A new muffler will smoke until the paint anticorrosive coating burns off. And the exhaust gasket could be leaking blowing hot exhaust in the spark plug boot.

Click to expand...

Thanks ILENGINE I really appreciate that insight and information. I didn't know that about the anticorrosive coating.

That last point makes perfect sense as well. I really appreciate all the help from everyone.

"but it's still getting so hot'

Click to expand...

do you care to explain that statement? It appears from your statement the overheating problem began before the carb was replaced. Also - did you replace the coil, and if so under what circumstances?

sgkent said:

do you care to explain that statement? It appears from your statement the overheating problem began before the carb was replaced. Also - did you replace the coil, and if so under what circumstances?

Click to expand...

Yes, the overheating was an issue before the carb change. The carb was changed due to surging (which was fixed with new carb) but overheating persisted.

The coil was replaced because the wire melted due to overheating.

The muffler was changed last due to the muffler making a rattling sound when removed and shaken.

what problem came first?

How much use had the engine seen without that problem before it happened?

engine model number and serial and/or at least Pony model number and serial.

What spark plug number are you running in it?

sgkent said:

what problem came first?

How much use had the engine seen without that problem before it happened?

engine model number and serial and/or at least Pony model number and serial.

What spark plug number are you running in it?

Click to expand...

MODEL NUMBER
13AN77KG011

SERIAL NUMBER
1D239B462010
00001

The spark plugs have been 3 different ones, not sure the model numbers off the top of my head, just the called for one by the manual brands being Champion, Autolite, and not sure of the other.

The surging seems to have been happening with the overheating muffler and melting coil wire, though now with a new carb the engine runs fine but it still overheats.

Kmh72412 said:

I checked cooling fins, no debris or blockage.

Click to expand...

As in clean as a new engine off the dealer floor? Clean as in super clean? All around the head and other areas?

it melted a new plug wire after the new carb?

slomo said:

As in clean as a new engine off the dealer floor? Clean as in super clean? All around the head and other areas?

Click to expand...

Yes, everything is very clean, the cooling fins have no grime or anything on them or relatively close to them.

sgkent said:

it melted a new plug wire after the new carb?

Click to expand...

Sorry, it has melted 2.

The first/original one and a second one even with a heat shield wrap on it.

I caught on and started to pull it off the plug and put it to the side when it started smoking to ensure it didn't stay exposed to the heat (but obviously this has been problematic in trying to fix it, having to disconnect the spark plug everytime only after 1-2 minutes of running).

Missing any cooling fan blades off the flywheel?

For example....

slomo said:

Missing any cooling fan blades off the flywheel?

For example....
View attachment 61969

Click to expand...

I believe several are broke but not to that extent in photo, just 3-5 that are broke in half.

Do you think several of them like this would make a big difference in it's cooling ability?

Kmh72412 said:

I believe several are broke but not to that extent in photo, just 3-5 that are broke in half.

Do you think several of them like this would make a big difference in it's cooling ability?

Click to expand...

Yes.

Engine was designed and manufactured with x amount of cooling blades. Just like removing one blade off your living room ceiling fan. Not going to cool as well.

Fix the cooling fin situation. I would change the oil while you are at it. You've superheated the entire engine.

slomo said:

Yes.

Engine was designed and manufactured with x amount of cooling blades. Just like removing one blade off your living room ceiling fan. Not going to cool as well.

Fix the cooling fin situation. I would change the oil while you are at it. You've superheated the entire engine.

Click to expand...

Okay, yeah I'll get the new flywheel fan.

Thanks. I really appreciate your help Slomo.

Also, any tips for getting the flywheel bolt off? It says you have to put a string in the spark plug hole to stop the piston from moving so it stops turning but I would rather not stick anything in there.

Is this generally safe to do though?

Kmh72412 said:

Okay, yeah I'll get the new flywheel fan.

Thanks. I really appreciate your help Slomo.

Also, any tips for getting the flywheel bolt off? It says you have to put a string in the spark plug hole to stop the piston from moving so it stops turning but I would rather not stick anything in there.

Is this generally safe to do though?

Click to expand...

Impact gun and an impact socket. Only way to fly. Either electric or pneumatic take your pick.

For removing flywheels, air hammer and a prybar.