Re: oil light came on...
Like EricV said: the light is level, not pressure activated. So if the oil shows in the window, then the switch is fubar. Or sticking. It is item number 8, on the Electrical 1 page of the 2012 Super Tenere parts list. It has nothing to do with oil pressure, which is what triggers the light in most cars. Merely level in our case.
Dry sumps for the uninitiated:
Oil is scavenged (drawn out of) the transmission, clutch housing, crankcase, etc. A pump does this, and in our case, pumps it into a "tank" formed by the engine castings under the transmission. Other bikes such as the original Honda 750 Four and Harleys and some others use an actual tank, often below the seat in place of a frame side cover. Some, like Yamaha's SR/XT 500 series used the hollow frame backbone tube and front downtube as the tank. Doesn't matter much where the tank is, just that there is a tank. Yamaha first used this in-case style to my knowledge in the TX/XT500 twin of the early to mid seventies. The idea is to have sufficient oil without a really tall/deep engine made that way by an oil pan with reasonable capacity. Another advantage is reduced 'windage", where the oil is whipped into a froth by the rotating crankshaft and other things. By extracting the oil from the operating parts with a scavenge pump, and then getting it to whatever is being used as a "tank", not only does the oil not become fluid friction, but cools off some and also has a chance to rid itself of excess air. The fluid friction becomes a problem in wet sump four strokes because of overfilling or excessive windage. Imagine trying to run through waist deep water vice perfectly dry, soft ground. That's why overfilling four strokes is such a big no-no. In the old V8 hot rod days, they made add-on windage trays to bolted onto the bottom of the main bearing caps, separating the rotating crankshaft from the sump. We get this free of charge by our dry sump system.
From the tank, the oil is drawn into the supply pump, a different set of separate pump rotors in our pump assembly, which pumps the oil around around the engine under pressure. Most scavenge pumps are high volume, very low pressure pumps compared to the supply pump that pressurizes the oil system.
a last benefit of the dry sump system is that the oil supply pump pickup is usually, but not always, submerged deeper into the oil tank, drawing off the bottom. This has two benefits: A) G-loads and hills have a much harder time moving the oil away from the pickup which would cause oil starvation. The old Honda 100s and 125s from the early seventies would lock up if you did prolonged wheelies, as the pickup was up front. B) The other benefit is if you bust off a gear tooth or something else, it seldom ends up in the tank, because the scavenge pump system is generally set up to avoid debris. That way, the supply/pressure pump can draw off the absolute bottom of the tank, not a bit up to avoid debris.
So: that's why I have adopted the following method to check the oil. It has to be consistent to mean anything. I usually store the bike on the centerstand in the garage. After wheeling it outside and starting, I let it run for about a minuet or so, on the side stand, but that isn't important. What is important is I shut it off, get it level with both tires on the ground, and stoop down and look at the window. If the air temps are colder, then it tends to be at the lower mark, if warmer, then the upper. But always between the marks. Because I do it the same way, every time, I eliminate the differences caused by a really hot engine vs a not so hot engine, a hard ride vs an easy one. I always check before the ride, don't care about it before i put it away. If the engine isn't running, it doesn't care either. I'll add a caveat that it always shows full to over full if hot. But the amount of perceived overfill has a lot to do with temperature. Which is why i do what I do. After shutoff, there is some drain back into the forward crankcase sump, which is why i let it run for a minute or so before I check. that way, the scavenge pump can do it's job.
Sorry for the saga, but that's how it works.
::26::
