In comparison with the standard intake hose, the bgm PRO air intake hose has a higher volume on the side of the carburettor. The air intake hose is available in two different connection sizes for the carburettor: 40 mm (for example Dellorto PHBL 25, PHBH 28 and 30) or 50 mm (Keihin PWK 28, Polini 28 ? 30). The connection size on the side of the air filter is equal to 42 mm so that you can use the intake hose either with the genuine air filter box or with a foam air filter.
In the download area you can find the chart which shows the difference between the standard Lambretta dl/GP air intake hose and the bgm intake hose. The comparison was made using the Racetour cylinder 225, crankshaft with 58 mm stroke, Keihin 28 PWK, bgm air filter box and bgm Big Box exhaust.
Another significant advantage of the bgm PRO air intake hose is the drain system at the bottom of the intake hose: the fluid expelled from the carburettor does not accumulate in the hose and this prevents the idle speed system from clogging.