TT will argue that all these people didn't understand the design and neglected maintenance. It's your choice.
I will also argue that the US models don't have the inlet restrictor cover (favored by those speaking german) which causes very low pressure levels inside the filter box.
Further, there appear to be two different lengths of pipes on the breather element holder which changes the route the breather fumes take to reach the carb inlets. My bikes have the longer one, don't have the German favored filter box inlet restrictor, and didn't foul the paper element when I still used one. Since the US models don't have the big pressure drop caused by a small inlet restrictor, the filter is the first thing to present a pressure drop to the inflowing air (on US models). Wet a piece of paper and it turns back into limp pulp. The paper element fibers react in a similar way. If there exists a major pressure drop across its membrane, the differential behaves as a compression device, mashing the fibers closer together. As the weather becomes damp, the paper fibers begin to revert back to pulp, deform, and it collapses into itself. If your induction is like the US models, then a collapsed filter becomes much more significant at making a bigger pressure drop and the carb mixtures become too rich to the point of fouling spark plugs. I speculate the tiny inlet restrictor for German models is there to extend filter use so it won't be the major contributor to pressure drop effects. ...maybe. But, I don't really care about fixing those models, just the ones the rest of the world uses. Honda stipulates for the US models that the filter be replaced at 1 year intervals. In my climate, the paper filter always began sooting the spark plug mid to late rainy season and no amount of "cleaning" made it work as well as a new paper filter. When Honda raised the filter prices to $50 per item, I switched to the Uni foam type which is cleanable and reusable. I could never find a way to return the "fluff" back to original in the paper filters, and there is simply no way to completely clean all the dirt out of a paper filter so it doesn't become a significant player in the inlet pressure drop. If you have a different inlet mechanism to provide the most significant pressure drop for the inlet, the effect of a clogging filter will likely be difficult to notice. And, if both sides of the filter element have the same pressure, the compression effects upon the paper are reduced.
My 1976 model didn't come with that breather thing and I can assure you: there's not much pollution.
Based on what measurement data, do you offer those assurances?
The EPA, and even earlier the CARB, identified crankcase vapor as a major contributor to air pollution and began mandating crankcase recovery systems for autos in the 60's. They didn't bring pollution focus onto bikes until the mid to late 70's. I believe it is pretty much standard equipment on anything made since the 80's.
Here in California every car newer than 1975 must get a bi-annual smog inspection. Right there on the inspection check list is to verify the crankcase breather recovery system is functioning. The breather recovery system is nearly a no cost, no downside effort to reduce completely unnecessary pollutants in properly designed and maintained systems.
Perhaps the other side of the Atlantic gets a constant air replenishment off the ocean and pollution effects get shifted to other countries which cannot control the source of the pollution upwind in another country?
What did you do with the breather hose...mine is just pointing to the ground just past the battery...not sure I love it.
Imo. You should not love it. Unless, you can permanently hold your breath, and teach everyone else how to do that, too.
