The rotary slide control of the Largeframe Vespa models (starting from the VNA models approx. 1962) up to today's PX is as clever as it is sophisticated.
On the 200cc engines, whose rotary valve is wider than that of the 125cc models, power of over 30hp is regularly conjured up with a good power band. We also offer flow-optimised MRP rotary vane suction nozzles.
If this is not enough power, a membrane inlet must be installed. This allows the former rotary vane inlet to be enlarged without having to consider its sealing effect. The diaphragm integrated in the new intake manifold fulfils the gas control requirements. A carburettor with more than 30mm cross-section can be used in a meaningful way.
The diaphragm intake manifolds manufactured by MRP in Germany are intended for use with the powerful diaphragm type of the Yamaha RD350LC YPVS. The nozzles are available with a stainless steel tube or a flat upper part CNC machined from aluminium. The quality, fit and possible performance are worth every cent.
A big advantage of the MRP spigots is that they neither need an adapter plate nor that the motor housing has to be welded on. Suitable diaphragms are available from BGM, V-Force or directly from Yamaha. Racing product without road approval. However, the suction unit can be registered with the TÜV with a single inspection.