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.
FC Isle of Man's trip to Barnoldswick Town postponed
Hockey: Bacchas Men's B looking to keep up flawless league form
Rugby: Ramsey at home to face Dukinfield
Football: 'Take Two' for FA Cup first round clashes?
Ravens on the road at Barnoldswick Town