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Question bout XR 80 &100 head damage??


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Has anybody figured out what causes the oil starvation issue to the camshaft, causing the head to become garbage? Is it because some people do not keep track of the oil level, or is there some mechanical issue?

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Oil starvation is caused by low oil level in the crankcase.......oil pump runs out of oil to pump. Also at low oil levels oil temp runs higher, oil over heats, breaks down faster, can't lube as well, etc......not good. The cam uses what is called a plain bearing. To live, plain bearings MUST have a "steady" supply of "clean" oil. Next problem, crankcase oil is usually not changed often enough. Often looks like a thin mud with a burnt smell to it! Remember, these engines run hot and the clutch and trans also run in this oil so it get lots of contamination in it........needs to be changed often. And many times the "wrong" engine oil is used. Plain bearings are a very common bearing that work well, but require basic maintenance. One last thing is running the cam chain too tight..........not good. Adds extra pressure to the left cam bearing. When I read how people attempt cam chain adj it's pretty clear this is often a problem also. As for oil passages just plugging........I've only seen it when someone has had the engine apart and managed to plug it. Any of this make sense........?😏

Old School Al

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That's what I was expecting to hear, I just picked up a 94 XR80R and a 2000 XR100R for next to nothing, and both of them have top end issues. I have been looking for a head for the 100 and there does not seem to be any out there except buying a new one. 😏

Thanks for confirming my suspicions about what was causing this problem.😏

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