Tuned engines will be allowed again at the two sidecar races at T.T. 2014.
Organisers have decided to return to "Open Class" regulations after talking to many of the competitors.
For the last two years, crews were not allowed to run tuned engines in their outfits in an effort to bring costs down.
However, after consulting with the teams, operating budgets appear not to have signicantly reduced.
Football: Early premier league bottom two to meet this weekend
Several with chance to close down Castletown in Division 2
Boxing: November fight date confirmed for Sam Rennie
Manxman to face Patrick Liukhoto later this year
Cricket: Lucy Barnett named August ICC Women's Player of the Month
Island player scoops award after standout international performances
Shooting: Kirkpatrick takes the win by one
Competitor also claims high gun in fifth summer sporting league round