Bring a large pot of lightly salted water to a boil.
Add pasta and cook for 8 to 10 minutes or until al dente; drain.
In a medium saucepan over medium heat, combine reserved mandarin juice, reserved pineapple juice, eggs, salt, sugar, flour and lemon juice. Stir well and bring to a boil.
Remove from heat and pour over cooked macaroni. Chill overnight in refrigerator.
Stir together juiced macaroni, pineapple, oranges and whipped topping.