You can install a Dellorto Sha15/15 with the handlebar choke on the Motobecane 50V with the use of a shorty intake, you may use the stock 10mm intake or a bigger 15mm intake. With the 10mm you will need to insert a small carburetor reducer on the shorty to accommodate the Dellorto size. You can salvage the reducer from a Gurtner R2-10 carburetor. You are not restricted to the long bendy Motobecane intake. The shorty makes for a better fitting and access. You will not have any clearance problems with this setup that you have with the long bendy intake. And also there are no modifications to be made to the throttle mechanism. I have used this setup on a 1977 50L, 1978 50V and 1979 50V. The slide comes up and down all the way when twisting the throttle grip. It may be necessary to make the small modification on older models. I use a 59 jet on all my mopeds with this setup This is the 10mm shorty setup.