 Here's what Mikuni VM's typically are equipped with. 
Keihin needle jet inner hole diameters 2.9mm for PWK33-39, PWM38, PJ34-38, PE36, FCR28-41 2.6mm for PE26-28, PWK26-28, PE20-24 Heres what PWKs are often equipped with:  DellOrto calls their needle jet an 'atomizer'. 2 stroke atomizers are labeled AQ, AU, AV, AS, AB, AF, AR. The hole diameter is known by dividing the atomizer # by 100. This site lists the atomizers and their carburetors. This site also sells atomizers without listing any spec but their hole diameter. Treatland sells genuine Dellorto jets. Here's what DellOrto carbs are often equiped with:   |