missin44 it is a fact that clean air regulations go into effect for motorcycles in the year 2008. HD says they can get the air cooled engine through emissions however every other manufacture that has tried to do that in the past has failed. VW, Porsche and a couple of others. If they do get the air cooled engine through emissions some how you can bet it will see some big changes not to mention you will no longer be able to change those pipes without giving up your EPA regulations and will not be able to pass emissions test if you live in a major area that has IM240 mandated.
Actually clean air regs for motorcycles go into effect nationally for 2006, Tier 1, 1.4%HC+NOX. Tier 2 is 2008, much more stringent, .8% HC+NOX resulting in air injection, catalyst, ect. (Tier 1 2004 in CA, Tier 2 2006 in CA). Just read an article on such regs.
I believe the new Buells with EFI and o2 sensors now meet the standards set for 2006 so there is hope. Remember these motors are based on the sportster platform. Eric Buell performed some magic with these.
o2man98 the problem is cylinder temps, carbon and O2 mix to create CO2 at 2500F and the problem with an air cooled engine is keeping the cylinder temp below that point. With a water cooled engine that is not a big deal when you put an egr (exhaust gas recirculation valve) valve in place to reburn some exhaust gases you can kill the heat by starving O2 from the engine. Like I said the problem will be that even if they make it meet standards the air cooled engine as we know it will be so complex in order to keep these standards that you won't be able to change anything. If you have to deal with IM240 there simply is no cheating. Our machine hooks upto the state and must be plugged into your aldl and then data is sent out direct from the dyno and the sensors. If you fail you have to make repairs in order to make the car pass, it's just that simple.