I just received this link to the EPA LOG or Letter Of Guidance regarding building EPA compliant bikes. If you build a bike following the LOG, there are no restrictions on use, number of units you build or ownership time.
http://www.mrf.org/pdf/EPALetterofGuidance.pdf
Here is the e-mail I received. It summarizes the PDF.
The Environmental Protection Agency (EPA) has released their long awaited Letter of Guidance (LOG) for aftermarket motorcycle engine emissions certification. This LOG will allow aftermarket motorcycle engine manufacturers to sell EPA compliant engine packages to individuals and small volume builders and manufacturers. "I would like to thank the SMROs who assisted the Motorcycle Riders Foundation (MRF), American Iron Magazine, and key members of the Motorcycle Industry Council, V-Twin Aftermarket Committee: Brett Smith from S&S Cycle and Ted Sands from Performance Machine", said Dave Dwyer, MRF Board of Directors. "With their commitment and assistance this LOG retained the exemptions currently in place and increased the choices available to builders of custom V-Twin motorcycles." Individuals and small volume motorcycle builders and manufacturers will be able to use these engines to build EPA compliant motorcycles without having to go through the emissions testing process themselves. By using these approved engine packages an individual may build and ride as many custom motorcycles as they want, as long as the engine package is not altered in a way that will increase exhaust emissions for any pollutant. There is no EPA restriction on time of ownership, or restrictions on the sale of these compliant motorcycles like there is on the one per lifetime EPA exempt kit bikes. To be EPA compliant the builder must keep the total weight of the motorcycle and the ratio of the engine speed to vehicle speed in high gear within the limits for the engine package they choose to use. If the engine was certified using a catalytic converter, that must also be included in the exhaust system. No engine modifications are allowed, similar to the anti-tampering rule for all other motorcycles, for the engine to remain EPA compliant. The MRF will continue to inform the nation’s riders of any action by the EPA which impacts motorcycling. To view the letter sent by the EPA to the motorcycle manufacturers click here: http://www.mrf.org/pdf/EPALetterofGuidance.pdf 
