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Discussion Starter #1
Okay, so now I know why they sold me that Cub Cadet mower so cheap. The engine overheats are about 30 minutes. Here is what I have tried(its a 2006 engine two cylinder 4 cycle 18 horse):

  • Replace spark plugs twice
  • Clean carb and set to super rich mixture
  • Change oil and filter twice
  • Replace fuel pump
  • Replace fuel filter

It used to only make it 20 minutes, and now it makes it 30 minutes. I would say it was the oil change. Here is what it does and always did:

Runs great right until shutting down to overheating. I don't really think it gradually looses power. Its like it cuts out and if you don't instantly disengage the PTO it will die and you have to wait like 5 minutes before starting again. Something that is really odd is the PCV line that feeds back into the air intake will release a ton of smoke or steam or whatever when it dies. Also, if you turn off the PTO and it doesn't die, if you quickly lower the throttle it will also smoke through the PCV line. It also seems to use oil, so I'm guessing the PCV is leaking or something but don't know much about it. I thought it may be the rings, but checked the spark plugs for evidence of oil in the chamber, and there is none.

Any ideas?
Thanks
 

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What is the brand and model number of the engine on your unit?

Have you checked to make sure the fuel cap is properly venting?

Have you tested for ignition spark when it dies?

Is the oil level correct?

How did you adjust the carburetor to run rich?

When an engine overheats, they usually loose power and run poorly, rarely do they just die.
 

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Discussion Starter #3
No, not tested the spark because I think what is happening is the magneto is too hot. Oil level is good. Fuel cap is venting. It may loose power but I don't think so. On this carb, you can adjust the low idle speed and fuel, so I opened up the fuel nearly all the way.

Thanks, sorry can't get the model right now, but its a horizontal shaft command engine.

What I'm really curious about is the PCV line smoke stuff.
 

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You should test for spark when it dies the module may be bad and not due to overheating.
 

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Discussion Starter #5
Okay I will, but can a bad module cause overheating? I mean you can feel the heat rolling off of it when it quits. It is indeed overheating.
 

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Air cooled engines get hot, very hot infact. Unless your cooling fins are plugged with debris grass etc and or there is a problem with the cooling fan on the flywheel, I doubt your problem is an overheating engine.

If you really suspect the engine is overheating, make sure the flywheel key is not partially sheared, throwing the ignition timing off, or if you have a s.a.m. equipped engine that the s.a.m. is good. A faulty ignition module could also change the timing, but I don't see that very often.
 

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It used to be in years past that if you were considering buying a used car and wanted to know what the condition of the car's rings were without using a compression checker, then you would drive the car in low gear (low range if an automatic) and accelerate to about 4 grand in rpm and let off the accelerator. Then you would look behind in the rear view mirror to see if smoke was coming out the exhaust. If you saw smoke, you knew the rings were worn and oil was being sucked by the rings into the cylinders. This was before pvc valves. Point is this : if you see this much smoke coming from the pvc valve, then chances are you might have ring problems. Also know that ranked according to their energy level ( think energy = heat) diesel about 11% more than gas and motor oil has the most of all. So if you're putting more energy into the carb, it seems natural it would run hotter.
 

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you can thank the EPA.. for this..

30yearTech is on of the best internet troubleshooters around for lawn equipment.
and it is very hard to trouble shoot over the internet...
 
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