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2021 Africa Twin
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My 2021 CRF1100L has gone through 4 quarts of oil in only 6000 miles my factory warranty ends in December. I don't want to put it in the shop during prime riding season. Will likely take it in mid November to get it diagnosed.
 

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Regardless of how it happened, you found the problem. I've seen this once before in an engine. Oil was contaminated during an oil change. I've seen it to a lesser extent by extended oil change intervals combined with hard use.

If you run any engine hard, hot, or both you need to shorten the oil change interval.

This kind of scoring can also occur if you run the engine hard without letting it warm up. Conversely, if you tamper with the thermostat and run the engine too cold, this can also happen. The piston and cylinder are designed to run at the same temp, if the cylinder runs cooler than designed, there will be excessive ring wear like shown. Haven't seen this because the engine was trashed, but this is why you service the thermostat in a boat motor on the regular.

Lots of variables, but hopefully that gives you some idea as to what might have happened.
 

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I assume you are looking at your cylinder walls through a spark plug hole with a scope/camera. If so it looks like a bucket of dirt went through your intake. Those look like serious grooves. What does the inside of your airbox look like. I’m surprised it runs, as bad as that looks. Have you measured compression or done a leak down test?
 

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Discussion Starter · #28 ·
Regardless of how it happened, you found the problem. I've seen this once before in an engine. Oil was contaminated during an oil change. I've seen it to a lesser extent by extended oil change intervals combined with hard use.

If you run any engine hard, hot, or both you need to shorten the oil change interval.

This kind of scoring can also occur if you run the engine hard without letting it warm up. Conversely, if you tamper with the thermostat and run the engine too cold, this can also happen. The piston and cylinder are designed to run at the same temp, if the cylinder runs cooler than designed, there will be excessive ring wear like shown. Haven't seen this because the engine was trashed, but this is why you service the thermostat in a boat motor on the regular.

Lots of variables, but hopefully that gives you some idea as to what might have happened.
My motorcycle has always been serviced in a timely manner, and in hot conditions, but the oil has been changed no later than 5k. Filled with Eni 10-30
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Discussion Starter · #30 ·
I assume you are looking at your cylinder walls through a spark plug hole with a scope/camera. If so it looks like a bucket of dirt went through your intake. Those look like serious grooves. What does the inside of your airbox look like. I’m surprised it runs, as bad as that looks. Have you measured compression or done a leak down test?
Didn't measure compression. Yes, it was checked with a digital endoscope.
What happened to the filters at 12500 km?
 

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I rule out damage to the air filter, since the zhor was noticed during the run-in.
Let us know what it was after the engine rebuild. There is a lot of visible grit in the oil, it also looks on the brink of sludge too. If that oil is at proper mileage and time interval, it looks like you’ve had no air filter since new and even during run in.
 
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