That intake valve appears to be chipped or something...View attachment 87482
#1 cylinder exhaust valve. 2014 Super Tenere w/199,003 miles.
With that many miles, what has been your history on checks and adjustments? Other than that one valve it looks pretty clean given the miles.View attachment 87482
#1 cylinder exhaust valve. 2014 Super Tenere w/199,003 miles.
I guess if you do lots of long distance riding, it'll last longer, much less stop and go, more linear riding.Astonished to hear the timing chain was shot at such low mileage.
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To me, this looks like a classic example of a "Burnt" exhaust valve.View attachment 87482
#1 cylinder exhaust valve. 2014 Super Tenere w/199,003 miles.
Aren't the larger valves the exhaust?To me, this looks like a classic example of a "Burnt" exhaust valve.
Usually this is caused by the valve adjustment becoming too tight as the valve/seat wear. This in turn causes the valve to overheat due to not spending enough time on the seat to cool down.
Check your valves at the recommended intervals.
Adjust them if they are too tight.
Learned my lesson for the day...Large valves are intakes. Classic example of a burnt valve.
~G
We already know that there is a high percentage of probability that the valve failure has been due to a tight fit ... but the poor closing of the valve may also be due to an excess combustion temperature, which causes the valve to expand. Outside its parameters, it tends to deform and does not make a perfect seal and the heating process due to lack of heat dissipation increases. That is why I was asking for an “excess combustion temperature”… ..perhaps “a reflash”…. ”Fuel with minerals that stick to the valve and generate hot spots”…. ”Ignition corrections by reflash”… .etc … .If we rule this out first… ..we would increase the percentage that the cause of the failure was due to an over-tight fittoo high combustion temperature ?? …….
I'm not sure I understand the physics why different riding styles would affect timing chain life. It experiences the same loading regardless of throttle application, unlike say a final drive chain. In fact the largest variable the chain would see is RPM, which to my thinking would be worse for long distance, higher speed riding.I guess if you do lots of long distance riding, it'll last longer, much less stop and go, more linear riding.
Usually in my country, which is much smaller than yours ( less than 350 miles, from north to south, and 135 miles on the widest part....),, the miles on my bike are considered high....most portuguese guys wouldn't buy it on that alone....
Abrupt/snappier throttle on and off puts shock loads on the chain and likely is the biggest wear contributor.I'm not sure I understand the physics why different riding styles would affect timing chain life. It experiences the same loading regardless of throttle application, unlike say a final drive chain. In fact the largest variable the chain would see is RPM, which to my thinking would be worse for long distance, higher speed riding.
I don't recall, and too lazy to look it up. Is there a prescribed length limit or check in the manual?I dunno. I think a lot of perfectly good timing chains are getting changed unnecessarily.
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No, nothing listed on the maintenance schedule about the timing chain.I don't recall, and too lazy to look it up. Is there a prescribed length limit or check in the manual?
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Man, that's as clear as mud. (Especially as hard as it is to see anything in those tight spaces.) For those who elect to replace the chain, I hope you are replacing the sprocket/crankshafts also as a set. Otherwise you may be wasting time and money. Sounds pricey to do it all correctly.