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Around 6 months ago I have service my bike from the showroom, all the required things changed and it works fine.

Now, few days ago I was driving my bike and suddenly my bike stops, tried to start by button and kick too...but it not start. After this I go to a garage and mechanic inspect bike and tell me that your engine oil burnt out that's why bike stops. And then mechanic correct the things(changing engine oil, spark plug etc).

Here my question is what are the factors or conditions in which our engine oil burnt out and how we can aware from this...

Any suggestion please

  • Oil gets burnt from getting too hot. Is this an air cooled motorcycle or water cooled? Note, oil also turns black from engine combustion blow by. This generally occurs if there is poor sealing at the pistons / piston rings. New bikes require a specific break-in period (generally do not exceed super low rpm XXX) This enables rings to wear in cylinders correctly (to preclude blow-by) Possible broken piston ring? Possible poor break in period? – zipzit Dec 4 '19 at 5:47
  • @zipzit An Air cooled motorcycle. – Gourav Joshi Dec 4 '19 at 5:51
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    Are we talking Honda CB Shine, 125cc, carburated, 4 cycle ? – zipzit Dec 4 '19 at 5:59
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    Wow. Total price of bike is at top end of my repair estimate. So I'm way off on my global repair pricing, obviously. – zipzit Dec 4 '19 at 6:05
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    My little Honda generator has a 'low oil cut-off' but I've never heard of one in a motorcycle. – Jeeped Dec 4 '19 at 6:27
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I've never seen a low oil level switch on a motorcycle. Those that have an oil pressure switch typically only light a warning lamp if there's no pressure - but don't prevent the engine from running.

I'd guess the reason it wouldn't start is that the spark plug(s) was fouled by burning oil. This shouldn't be happening, and may be a symptom of damaged piston rings or valve stem seals. I doubt that the repair you paid for covered anything more than the oil and spark plug you mention. If the bike is running OK now, you should keep checking the plug for further signs of oiling.

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Blow-by is a scenario where the contents of the cylinder during compression and combustion (expansion) stroke escape into the crank case. In case of combustion it's generally hot gasses and fuel that enters the crank case. The fuel contaminates the oil and the hot gasses generate pressure. At normal operating conditions when the engine lube is splashing around the crank case, the pressure buildup causes the mist of oil to escape the crank case through the Positive Pressure Relive Valve into the combustion chamber where it's burnt off.

Reverse Blow-by is a scenario where the contents of the crank case are forced into the combustion chamber.

In both cases the main culprit is the Piston rings, excessively worn piston rings allow a lot of oil into the combustion chamber. In a normal engine a little blow-by and reverse Blow-by is fine, but judging by your condition, I would advise you to have your cylinder measured for any eccentricity and piston rings inspected.

Wrong grade of engine oil is also a factor.

A quick look into the oil level window located at the bottom of the engine does save a lot of hassle. Some bikes are even equipped with dipsticks.

I generally observe my oil level everyday, it give a clear understanding whether the engine is burning or leaking oil.

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