19-time T.T. winner John McGuinness will not be competing in the Leightweight T.T..
Phil Morris Racing and RLR Motorsports were developing a Honda CBR 500R but say a potential race winning bike won't be ready for T.T. 2013.
They say they have simply run out of time to competively take on the leading Supertwin contenders.
McGuinness, who is celebrating his 41st birthday, will be in action for the Honda T.T. Legends team in France this weekend at the opening round of the World Endurance Championship - the 24 hour Bol d'Or race.