Expensive Lesson

Now, I'm not always right about things but when I say to a customer who is talking about buying a bike with "starting problems", "Make sure you turn the engine over before you buy it because that engine is terrible for dropping valves...
Maybe you should listen to me. Turn it over by hand if you have to but make sure it does a full revolution.

This customer even called me while he was at the guys house and the guy told him it just needed a new ECM... It literally melted the starter with him there because it was loaded up against a seized motor... the guy couldn't possibly have had any more signs to avoid this thing and he still traded his truck for it... c'mon!!! Get that ADHD under control man.

The first visible sign something was wrong was the aluminum in the exhaust port.

So started further disassembly and found a broken valve tappet (which I have never seen before)

And then we found the ventilated piston...

And the culprit.

So, if you have a mechanic you trust, listen to them.

The owner did not fix this unit, it is almost impossible to find top end parts for this machine because they are known for doing this. And when people have a good head for one, you can bet your ass they charge a fortune for it.

Yamaha 5 valve heads are absolutely terrible for this failure, so much so, that I would never own one of their machines with a Genesis 5 valve head. Any of them...