I don't run trials tires on my WRR. I've used them for years on other bikes, but it is not what I'm after here: I want and have more aggressive traction. The TW301/302s that come on the bike are there for noise reduction. The same for the rubber sprockets and the rubber damper around the hub at the front disk. I think the western guys that do mostly dry rock are the fan base. I tend to avoid mud, but still find it. I like the almost excessive traction the D606s provide. Where the stock tires would spin when I would grab a handful, now I get launched. There's a type of Pirellis that are also aggressive and DOT, but I haven't tried them.
I changed to a Sunstar 47T and added a link plus two rivet master links when I installed the D606s. The stock chain and front weren't worn enough to toss. The Dunlop is a taller tire, and the WRR has first gear where second should be to begin with. In more level/less steep country than here, stock gearing is ok, but now my second gear is just a slight amount higher than where first used to be, and first is usable in the really tough stuff. You know how our Tenere's first is just a bit too tall? Same for the WRR. At least we can change sprockets on the WRR. My FZ had a lower first gear than either the WRR or the Tenere. That's nuts.
WCS has plastic, which includes the headlight surround:
http://www.wheelingcyclesupply.com/shop/1/4/index.shtml Otherwise, the dealer is the place.
When I called them for my skid plate, I had them put the large holes as shown in the wing in the photo in the front and also in the bottom; much better air flow to the cases and if something gets in the front, it flows out the bottom.
http://www.flatlandracing.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=FR&Product_Code=24-45&Category_Code=24-Yam
You wouldn't guess that just pulling off the stock plastic radiator shroud and replacing it with this would make such a difference in cooling, but it sure does. The stock rear shroud directs the heat back onto the engine, and in the process, kills the airflow. This warms your leg, but the fan seldom comes on now. The stock would also warm your leg, but much hotter as it let the engine get hotter to begin with.
http://www.flatlandracing.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=FR&Product_Code=12-40&Category_Code=12-yam
If you're going to ride in rock, then this guy is a must: The fin can be changed out separately. I noticed rock hits on the bottom of my chain guide, so knew if i didn't get one of these, I'd be out in the woods and take a disk hit, then either would limp home with a damaged disk, or be forced to pull the rear pads to get home. This is the most robust disk fin I've seen.
http://www.flatlandracing.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=FR&Category_Code=Rear+Disc+Protectors
I'm still trying to convince these guys (Flatland) into making me a bash plate for the Tenere. They have the Goldilocks touch: not too much, not too little, just right. The KTM crowd is their primary target audience. A coworker lives near to them, and he recommended them highly. I'm extremely happy to have followed his advice. As far as I'm concerned, they are the platinum standard for this sort of stuff.
I've left my pipe/engine/intake stock for a number of reasons. I have enough power for my needs, and where I ride requires it to be quiet and compliant, with spark arrestor, as much of it is State Forest. ( they ran the "Conserve the ride" thing there earlier this year. My backyard, sort of) I'm not out to antagonize the non-riders and the rangers with a loud bike. I'd rather they didn't know I was there at all. I've "snuck up" on lots of people in the woods so far, and that's OK by me. And last: even in the woods, I'm still getting 60+ MPG, which means I show the trip Odometer, and come out at 90 miles for a gas up, then go back in. Some of the FI tweaks and power mods lower the MPG to 45 or so. I would rather have the MPG so I don't have to replace the tank. I did do the flapper mod. Everything else is stock.
I find the air filter needs very little service. I serviced it when I got the bike (estate sale, 160 miles on it, $4300. Like new) I've checked it a lot and serviced it again, but it didn't need it. I ride in generally dryish conditions, with lots of stone roads and rock/clay trails. Some water, which I avoid if I can. Most of the trails are also used by the jeep crowd, so they tend to dislodge rocks in puddles and then I find them the hard way. Solution, go around mud holes/puddles.
Sorry for the saga, but that's the what and why.