In the 650 twins Ryan Farquhar got off to a flyer, led at Balladoole and kept it that way to the finish seven laps later.
Wayne Hamilton and Ian Lougher made up the other two podium places.
In the 250 race Chris Palmer, fresh from his 125 win took the early lead from William Dunlop and Phil Harvey.
Mechanical troubles put an end to Palmer's race on lap 2 letting Dunlop through to first place.
The Ballymoney man guided the 250 to a well deserved class win. Tom Snow was in second place and Dave Milling third.
Boxing: Tyson Fury's sons part of Manx squad to face Merseyside & Cheshire
Cycling: Rider views sought on latest MTB series
Football: Manx quartet feature in Tranmere Rovers victory
Tennis: IoM team confirmed for 2027 Island Games