by Warkton Tornado No.1 » Wed Jul 22, 2020 3:42 pm
All of those carburettor's are tailored toward modern engine requirements, which with respect to two strokes, are notable by their 'guillotine' slides, being very narrow in the cross section of the carburettor. Main body materials, tops, body inserts (Venturi shape) are just the basic variations.
An exploded diagram for all to see is available on websites, including Eurocarb.
IMO the range of VHS are very adaptable, capable carburettors that are designed toward gaining the sort of performance you would anticipate @ the top end of the range of carburettors available to buy.
The Dell'Orto's homologated to Rotax karting are often available to buy in very good, used condition & worth looking into. Similarly, engines in Aprilias & Cagivas use the VHSB 34 LD which can be a good set-up on TS's. One I have to hand, has the one-piece screw on cap with the darker grey (magnesium?) body. BTW, the '34' has a shaped Venturi insert, more like 37 mm in places, but don't let that put you off.
I suspect that carburettor's from Keihin, Mikuni & the PWK's such as KOSO, OKO may be as good & the physical size may well be a deciding factor in choice, especially if air filtration is a factor. Another significant factor might be choice, & currently my belief is that a 'good' PWK clone offers supreme value for money (& they operate extremely well with an air filter!)
ALL of the PWK's like ANY carburettor should be stripped down & checked/blueprinted prior to use IMHO.