The H2 SX is a special motorcycle and does require some special maintenance related to its supercharger and rear hub
1) Spark Plug maintenance: Like any boosted vehicle if you run them hard you musty keep the plugs fresh. The extra pressure created in the cylinder by the supercharger is very hard on spark plugs. The same as the other bikes in the H2 series, cylinder #3 seems to have the most issues. The below picture is of the spark plug in my bike after 5000 miles from cylinder 3. I am pretty sure that my H2SX has had more dyno runs then any H2SX out there so my use is extreme. The only symptom I had was a weird vibration on dyno pulls,I could not feel it under normal riding and I did not do any street pulls once the vibration started. I changed the plugs again at 8000 miles and they looked fine. I don't think its a coincidence that most h2 motor failures are on cylinder #3. So if your running your bike hard , keep those plugs fresh
2) airbox oil drain: There are two of them. One in the front part of the aribox and one in the back. The front one just has a plug with a little bit of line and the back one runs to a small catch can. One of the poor design features of this bike is the crankcase breather and it how it sits inches from the supercharger impeller. I would love to come up with a good catch can design to eliminate this issue but because of the space constraints I don't see how it would work. I recommend removing the plug that is on the front part of the airbox and running a line down and T'ing it in with the other line so they both can run into the little catch can. This makes it super easy to empty on the regular. Keep your oil level in the middle of the full lines and do not overfill your bike with oil or it will exacerbate the issue of sucking oil into the supercharger. If you pull the top of your airbox off you will likely find some oil in it. Oil getting pulled into the intake stream is obviously not optimal for performance .
3) Air filter: The air filters on our bikes are insanely small for the amount of power the bike is capable of. This is the main reason we see such large gains when switching out the filter to one that can flow better. When thinking of air filters , think surface area. The below picture is of a filter from a Yamaha Fz09 a bike that with a good tune and exhaust might make 120 hp to the wheel next to the H2 filter. The Fz09 filter is at least 1.5 times the size!! The intake is forward facing with the super charger creating big vacuum sucking through this small filter. It all adds up to a filter that gets dirty very quickly and when dirty chokes down the bike. KEEP IT CLEAN! I am going to plug a product I sell, but this is why I sell the sprint filters. The filter is a dry filter and super easy to clean. Blow it out from the back side with compressed air and reinstall . With an oiled filter if you put to much it doesn't flow well and if you don't put enough it doesn't filter well. I never knew how much oil to put.
4. The rear wheel bearing have been identified as an area requiring extra maintenance and some came from the factory pretty dry. I recommend every other rear tire change, greasing the bearings. Champ87 from h2sxowners forum has been gracious enough to let me use the really great guide he came up with. Thanks Champ