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Honestly the wet clutch doesn't do much to wear down oil. The biggest problem you have with oil wear on a wet clutch is having it build up a lot of crumb from the discs as they wear down. It may seem like a lot of wear and pressure and all that, but compared to the conrod bearings it's nothing.
As for the unit construction, not sure what you mean??? Like how everything is in one combined on the same oil?

Tranny gears chew up oil molecules and don't really help oil longevity, but nothing to get overly worked up about. Just change the oil at regular intervals, use decent oil and you'll be fine.

Wrider wrote:Honestly the wet clutch doesn't do much to wear down oil. The biggest problem you have with oil wear on a wet clutch is having it build up a lot of crumb from the discs as they wear down. It may seem like a lot of wear and pressure and all that, but compared to the conrod bearings it's nothing.
As for the unit construction, not sure what you mean??? Like how everything is in one combined on the same oil?

I don't mean that the wet clutch wears down the oil per se but that most wet clutches don't like old oil. For example my KLX will get harder and harder to put into neutral when hot as the oil ages.

Unit construction is where the engine and the tranny are united in the same casing. The tranny gears will throw tiny shavings in the oil which the engine parts get exposed to. Also as Buzzz mentioned the shearing effect on the oil from the tranny gears. Then in turn the tranny gears get exposed to the contaminated oil from the engine.

I'm not really agreeing/disagreeing with you. Just wanted to know what your thoughts were as someone that earns a living doing this.

No I know it's cool. Sorry been a "opposite of heaven" week for me so I've been a bit short.

The thing on the Shadow is that it's not being beat on usually, it's relatively low power for the engine size, and it's pretty relaxed in general, so the bike really doesn't grind down the oil like say a sportbike would. You also have less friction modifiers that tend to destroy the other elements in the oil when exposed to heat, so that helps a bit as well.

One of the reasons I've been so paranoid is that I do beat on mine pretty regularly. Only reason I have a shadow was because I couldn't afford the insurance on something sportier when I went to get my second bike. But I rarely ride at a relaxed pace. One of the reasons I liked the shadow is that it was rather revvy for a v-twin, and I abuse that at every possible chance

Just for curiosity sake, would the engine's purposely lean A/F affect oil life? I'm not sure if unburnt fuel degrades oil, but I figured it could make it dirtier.

That last sentence may confusing. What I meant to ask was if having a leaner A/F could cause longer oil life due to less unburned fuel or are thes not related?

Hopefully they're not related If they are you've got more problems than your oil life.

The leaner mixture doesn't really affect it too much. Maybe gives you slightly less power than you would have otherwise. But not enough to really affect oil life.

Extremely lean condition will affect oil life by making the temp soar. It will also affect engine life as well.

Well if it's extremely lean sure. Other than that how it's adjusted from the factory it won't affect it that much.

Yes you are right. And with the stringent new emission standards, its become impossible for manufacturers to meet it with a carburated bike anyways. 2008 was the last year Honda sold my bike(XR400 Motard), as they were no longer able to meet the stricter Japanese emission standards for 2009. So now we have all these fuel injected bikes that are running so lean that they sputter and surge, some to the point of being almost unrideable at low rpms. And unlike their carburated counterparts, it is a much costlier fix on the injected bikes.