Well, that would make some bit of sense except for a couple of things...
1.) Wasp discussed at some length that the foam filters being fitted in Oz by the Aussie Yamaha distributor were, indeed, UNI-brand filters.
2.) Australia is the *ONLY* market where the foam filters are fitted, and again, they were specified *NOT* by Yamaha Japan, but instead by the Australian Yamaha distributor.
That's kind of the problem with foam filters... Their only real advantage is their ease of cleaning and re-use. In any number of comparison tests foam filters have been shown to have absolutely no air flow advantages over other popular media like oiled gauze or paper, and oiled foam filters for the most part do *NOT* filter dirt nearly as well as the stock OEM paper filter (though depending on foam density may certainly filter better than oiled gauze). Just a tiny bit of Googling readily provides tons of research data to prove that.
Oiled foam is great if you have vehicle that is going to be operated off-road so much and so often that it needs the air filtering media cleaned nearly every outing... Dirt bike riders would go broke replacing paper filters all the time, but note when say "dirt bike riders" I mean MX, hare scrambles, and enduro riders who operate their bikes purely off-road in the dirtiest, dustiest, wettest, muddiest conditions. Such are conditions that very few, if any, Super Tenere riders would be operating their bikes in. If you were operating your Super Tenere in conditions where you need to clean your air filter literally every ride then foam might make perfect sense... Otherwise I'm not so sure.
That's another problem with oiled foam filters...
One has to be very, very careful with how they are cleaned - i.e. with what method and solvent like soap and water, mineral spirits (what UNI Australia recommends, BTW), etc. - and with what oil is used on the foam. The wrong solvent, or the wrong oil, can destroy the glue at the seams or even cause disintegration of the foam itself (like you experienced). There are even some brand air filter oils that are not compatible with certain brand foam filters, so even choosing an "air filter oil" off a motorcycle shop's shelf is no guarantee that that oil won't turn your expensive foam filter to dust. Even light, and certainly heat, can destroy foam filters over time, so they need to be stored in a cool, dark, place. Needs to be dry, too, as humidity in the air can combine with the air filter oil over long periods of time to produce acids that destroy the foam's integrity.
In other words, foam filters are really meant to be cleaned, oiled, and even replaced, regularly. That's what we've had to do with motocross bikes for decades.
I'm not knocking them, either. As you mention, they have their place as long as you understand their limitations and required administration.
I'd be very concerned running without the airbox lid, for a couple of reasons...
1.) I wouldn't want the foam filters interfacing with the underside of the fuel tank
2.) More importantly, for the most part literally all engines that use an air filter greatly prefer an enclosed "still air box". One of the more interesting experiments about this was done by Kaz Yoshima when he was with Yoshimura back in the 1970's, and was written about in a couple of magazines. He showed, with dyno and track tests to prove it, that a proper airbox was vastly superior to the bank of "pod" filters so many people were using on big, inline-fours so popular at the time. And the difference wasn't just a little bit - it was dramatic.
I'm fairly dubious of anyone claiming any dramatic "power increases" by simply changing to a K&N-style oiled gauze replacement filter or these pod-style foam filters, and the reasons why are pretty simple...
1.) This bike has a pretty sizable airbox volume... far, far in excess of 1,200 cubic centimeters itself (I'm guessing it has an airbox volume exceeding 9,000cc's), and the engine only grabs 600cc gulps at a time. Granted, with high-RPM operations and certain ram effects the engine needs at any one time will be more than 600cc's, and even more than 1,200cc's, it is not going to need more than 9,000cc's or air at any one time.
2.) Reports from all sorts of Super Tenere owners (even yourself, IIRC) is that the stock air filter has better flow and more area than the bike even needs, as evidenced from most owners stated that when they changed or inspected their stock air filters it appeared not even all of the surface area was being used and that the filters were remarkably clean even after thousands upon thousands of miles of use. This pretty indicative that the engine had more than enough airbox volume and filter surface area.
3.) So far nobody has really done *ANYTHING* to a Super Tenere engine that would make it need to draw more air... No wild cams. No high compression pistons. No big-bore kits to increase displacement. Etc., etc., etc. The most anybody has done is to hang aftermarket mufflers and maybe a set of cat-less headers on it. Neither of those would increase the engine's breathing demands sufficient to require a larger airbox... At least not from what I've learned about engines over the years. It's one thing to claim an engine *needs* more air, but quite another to prove it. To do that would require back-to-back tests, with at least a dyno but hopefully with a flow bench as well, using the different air filters with the stock airbox, and then with any airbox mods that might be considered. Wouldn't hurt to spin the head up on a flow bench, too, just to see what kind of air volume it actually needs and can flow. Until all that's done the claims are all pretty much "snake oil".
Another thing concerns me here with all these different air filters...
On one hand it has been claimed that the oiled gauze filters (like the K&N, BMC, DNA, etc.) give a "performance increase", and now there's claims that these oiled foam UNI pod-type filters give a "performance increase"... OK, so where is the analytical proof of such a "performance increase" - i.e. dyno tests, drag strip tests, something, etc. - and if there is such a "performance increase" whihc one produces the largest one - the oiled gauze panel replacement filters or the oiled foam UNI pods? And how much of a "performance increase"?
Anyway, these are just some thoughts on the ideas of different air filters... YMMV.
Dallara
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