Thanks a lot for the inputs guys.
Now I haven't been able to take it to the shop yet, but searching around I've found the video below, which is *exactly* the same noise, but from another KTM engine (450 trail). Check the comments, seems like offroad KTM owners (whose engines probably share a lot of with ours) experience this weird noise a lot:
The guy did a battery of open-engine checks/swaps to no avail:
- Cam Chain Tensioner adjusted/changed: no luck (though in the comments others say this fixed)
- Valves checked: within specs, and still noise
- Primary gear & nut check: in great shape (though this https://youtu.be/KipHrQ4XsEg
and this https://youtu.be/c60_uF-K8SQ
Someone suggested cam chain guide rails being worn out, but no further inputs after that.
I've also found reports of such noise from bigger dukes (single cylinder ones).
: completely agreed! And searching I might give these guys a try, they have great reviews and say work on European brands Speed Motorcycle
. Up in bronx so an easy ride there and I can subway back (I can't from the KTM dealer easily).
: I'm that type of person too, and have always DIY'ed my things. However, living in NYC this is not an ordinary task. Living in an apartment without the proper tools/workbench/etc (and having the bike parked 5 blocks away at a 110$ a month cost) greatly limits any work on it :/
: thanks for the inputs. I've carefully monitored this, and is seems totally unrelated to the clutch: the noise is there in any gear, and in neutral, and with clutch pulled or not. The noise is directly related to engine revs, and sounds louder at some revs (so sounds like the rattling resonates more at some rev frequencies, suggesting that indeed is something mechanical)
: that's a nice idea!! Thanks for the input, and nice to know someone here from BR too
Let me know any findings you might have from your "hearing" !!
As soon as I have some inputs here I'll update you guys. And the saga continues....