IslandRoad wrote on 04/21/20 at 17:01:55:Dump the old gas.
Install a Yamaha Raptor Petcock (put a cap on the vacuum port on the carb)
Fill with fresh gas
New oil filter (don't put it in on backwards - because it will fit that way)
Fresh oil
Check the air filter while you're at it
Check if she starts (make sure the kill-switch isn't off)
Does it try to start?
If it doesn't try to start then chase down an electrical problem (safety switches, battery etc)
If it tries to start but won't, then stop trying to start it (you'll burn out the starter)
Chase down any fuel issues (tuning, float level, blocked jet etc)
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Great advise except I wouldn't waste my money on an oil change until it starts up after you replace that faulty petcock!
(But make sure you add enough oil to get it at least halfway up the glass when the bike is straight up. And take note of how much oil that is. The bike holds a little less than two quarts. Hopeful you need less than a quart, quart and a half.
)
Hopefully that's all it is.
If you ran it out of oil you would have either seized it up, fried the rings, or destroyed the lower bearings.
If it sized up, you would have known. It the motor would have ground to a halt and locked up the rear wheel. You would need to pull in the clutch the compensate.
If you fired the rings it would have probably kept running and then refused to restart after it cooled off. Unless the piston crown failed and munched up. You would have heard that. Same with broken valves.
Lower bearings just make a lot of noise, like a big hammer in the bottom of the engine, but the engine can run for a long time with bad main bearings (and cause a lot of damage to the crankshaft, rod and wrist pin in the process).