Hello,
I was doing the standard procedure valve clearance procedure on my 2021 GSA with 14,000 miles on it. The oil had less than 6k on it. And has been changed nearly by the book.
Please see photos: the high lift intake cam had a strange pattern on it, on one side of the bike. All the exhaust cam lobes looked nice and shiny. The other intake cam doesn’t have the same condition or at least no where to the extent.
Some important observations:
No metal shaving in oil
Next to 0 metal on drain plug
No actual deformation on the patterned lobe
It appears the pattern is only on the high lift lobe (it’s a shift cam engine; cam moves to from a low lift intake line to a high lift for variable valve timing)
Again, didn’t see it to the same degree on the other cams: the last photo will be the other side of the boxer engine for comparison.
The working hypothesis (all credit to a boxer engine guru) is that the pattern is from the wear additives being left behind under the high pressure and high shear working.
I am curious if anyone on here has seen this is other engines or if someone has more to add. I was quite worried at first admittedly, but after feeling the surface and not catching any peaks& valleys AND after talking to expert wrencher, I have since relaxed haha.
I was doing the standard procedure valve clearance procedure on my 2021 GSA with 14,000 miles on it. The oil had less than 6k on it. And has been changed nearly by the book.
Please see photos: the high lift intake cam had a strange pattern on it, on one side of the bike. All the exhaust cam lobes looked nice and shiny. The other intake cam doesn’t have the same condition or at least no where to the extent.
Some important observations:
No metal shaving in oil
Next to 0 metal on drain plug
No actual deformation on the patterned lobe
It appears the pattern is only on the high lift lobe (it’s a shift cam engine; cam moves to from a low lift intake line to a high lift for variable valve timing)
Again, didn’t see it to the same degree on the other cams: the last photo will be the other side of the boxer engine for comparison.
The working hypothesis (all credit to a boxer engine guru) is that the pattern is from the wear additives being left behind under the high pressure and high shear working.
I am curious if anyone on here has seen this is other engines or if someone has more to add. I was quite worried at first admittedly, but after feeling the surface and not catching any peaks& valleys AND after talking to expert wrencher, I have since relaxed haha.