Prayers for you and your wife. Not that this post will make you feel any better, but I experienced this same issue on my 08 YZ450 last year. 5 valve genesis head. 3 exhaust valves and 2 intakes. Short story, I completely rebuilt the motor and it only had 20 hours on the rebuild and was running very well. I put in a gallon of race fuel 102 octane (12.5-1 compression ) and went out for a trail ride. Mistake. its race fuel, and I didn't race.. I trail rode the bike that day. came home and drained fuel out of tank and carb as I knew it wasn't going to be used for a month or so. Came back 45 days later and kicked it over. Nothing. then kick starter just limped thru stroke and nothing, NO compression, nothing. Pulled cam cover and I could see daylight under one of the buckets next to cam, NOT good. Exhaust valve was in the stuck open position. Luckily, no contact was made with piston. But I had to tear it down and pull head. Upon further inspection, the valve stems were coated with fuel residue (race fuel ) and the guides were completely dry, which caused the valve to stick open, no lubrication on valve stem and me not racing the engine to get a complete burn of the race fuel. this left a residue on the valve stems (sticky). I cleaned all valves, installed new valve springs just in case, as stockers were still in spec, but put new ones in anyway. coated all valve stems with lube and put back together. Runs great with no damage. Your FJR should not have seized this way, unless your fuel quality on that last tank was questionable. maybe some water in the fuel? but you would have noticed a power fall off or poor running with H2O in fuel. it should clean up well, but I know the labor costs will sting. Hope your wife stays strong as I know you and your family have more important tasks ahead than your bike. keep us posted on the repairs, ask the tech to remove the valves (he will have to anyway to clean them and reseat them.) ask him to check for any fuel residue on the stems.
Have you used a 50/50 mix to clean injectors and carbon off valves with Seafoam ? I use it for winter storage no ethanol issues after a long winter. I've never used Yamaha fing free.
Exactly. A couple of things come to mind, a really rich condition which points to an EFI issue, a PAIR system malfunction where it was pulling crankcase gases without closing the valve, and possibly a rider issue if it was lugged for a long time. But what it isn't, is a fuel quality issue. You are right about the quality of gasoline sold in NA. Even if it's not Top Tier gas, the level of detergent mandated by the Fed's is more than adequate. Would have liked to get a nose on the oil. Really rich should show up in the pan and maybe the cylinder walls. A PAIR system issue should show up in the intake runners and clear back to the valve cover. The gunk in the cylinders looks suspiciously like the gunk that covers the reeds in the valve cover. But, I'm speculating without the motor on my bench. I just know it isn't fuel quality.
