This was a day without actual riding (other than about half a mile around the block).
Since I rode nearly 6000 miles on this trip so far, the bike was due for a service. This was actually the "large" 12k miles (20.000km) service, including valve check. All of the valves were within specs. So far so good.
The cam shift mechanism isn't as complicated as I though it would be, the cams have two lobes and the shift mechanism just moves the cam over to the one that is to be used for the current riding condition:
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| Shift Cam Valve Train |
The engine does a great job hiding the shifting process in terms of power delivery, but certainly not in terms of sound. It can be especially annoying when riding under cruise control and going at a speed that has the engine close the typical shifting point and then every slight incline/decline in the terrain will make the engine shift over the cams and mine makes a "popping" noise when this happens. Slightly annoying, it sounds like it has digestion issues ...
Tomorrow I'll try to get an early start to beat Hurricane Delta – I need to ride across its projected path and be west of it by Saturday. Otherwise I might get into some seriously bad weather. Shouldn't be too much of a problem though, I just hope my ears won't give me issues.
Interesting. I hadn’t thought of the valve timing shifting. From the cam profiles in the picture, it’s a pretty significant change.
ReplyDeleteIt is quite a difference in height, I was surprised. There has to be quite some electronic magic going on to keep the power delivery smooth. Still, these bikes make weird noises.
DeleteVery nice! Am still working on those 6k+ miles on my GS and am looking forward to getting my hands dirty on doing the next service - with your help, so you don't get out of practice. :-)
ReplyDeleteOf course. Ans now I also know what not to do - we dumped about half a liter of fresh oil on the ground due to the oil filter not being seated correctly. The tread had more resistance than I could apply by hand and therefore it wasn’t tight against the case to seal. Probably a badly machined filter and I didn’t check that it went all the way. First time for everything ... :-(
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