Here are the facts...
As part of the American Recovery and Reinvestment Act of 2009 (H.R.1) two new tax incentives were included for electric motorcycles.
The first is a tax credit in Section 1142 (H.R.1, pp. 214-217) which changes IRS Code Section 30 to allow for 2 wheeled electric vehicles to be included as a “qualified plug-in electric vehicle” in the overall plug-in vehicle tax credit. These vehicles which need to be able to drive on public roads, streets, and highways, are eligible for a 10% Federal Tax Credit up to a maximum of $2,500. This is a Federal tax credit, which reduces your tax liability by the amount of the credit; eg: if you owe $5,000 to the IRS and purchase an $11,000 electric motorcycle package, you would receive an $1,100 credit and now owe $3,900. If you are owed a refund by the IRS, your refund is increased by the amount of the tax credit.
The second is a tax deduction for state sales taxes paid on motorcycles under Section 1008 (H.R.1, pp. 203-204). This provides all taxpayers with a deduction for State and local sales and excise taxes paid on the purchase of new cars, light truck, recreational vehicles, and motorcycles through 2009. This deduction is subject to a phase-out for taxpayers with adjusted gross income in excess of $125,000 ($250,000 in the case of a joint return). In this case, since it is a Federal tax deduction, the amount comes off your adjusted gross income and reduces the amount of taxes paid based on your income tax bracket.