The standard setup on a beetle engine is a relativley small carburetor centraly possitioned, providing modest fuel flows along the inlet manifold to the cylinder heads. The inlet manifold has a preheat pipe running along its length (conected to the exhaust system), this helps to keep the fuel in vapour form.
You have a large carb/manifold upgrade so potential fuel flows are high, retaining the central location and not having a form of preheat (your set up does not appear to have any) will as your found mechanic says be prone to fuel drop out in the manifolds and can cause poor mpg, idle problems, stutteriYng to name a few.
Yes, as a rule carb upgrades are best done by utalising two carbs one each side mounted on short manifolds directly over the cylinder heads. Much more efficient.
Not sure your carb can be split thou:?
harveypj wrote: