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MRP Item number: MRP844

Intake manifold - Membrane intake manifold -MRP RACING- Vespa VNA,VNB, VBB, VBC, GT, GTR, Sprint, Rally, PX, Cosa - Membrane under SI carburetor

MRP RACING diaphragm kit for mounting under the SI carburetor sump (MRP844)

Option for repairing a defective rotary valve inlet or for retrofitting to SI carburetors

Plug and play on short and long sealing surface of many Piaggio, LML and tuning housings

Carburetor sump sits approx. 20 mm higher and approx. 20 mm further forward - more space on the frame than with many solutions

Note: Separate lubrication cannot be used with this set

119,00 €*

available immediately

Shipping weight 0,092 kg

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Description
Suitable vehicles

MRP RACING diaphragm intake manifold under SI carburetor (MRP844) - Vespa Largeframe

The MRP RACING diaphragm intake manifold under the SI carburettor sump is a practical solution for largeframe engines if the rotary slide intake is damaged or an engine that has previously been converted to a large diaphragm carburettor is to be converted back to the SI carburettor. The kit is fitted under the carburettor sump and thus creates a diaphragm intake without completely leaving the SI base.

MRP RACING MRP844 Diaphragm under SI Plug and Play Largeframe

What the set is intended for

Repair solution: If the rotary valve area is damaged, the diaphragm intake can make the engine usable again.

Retrofit: For engines that have been milled to diaphragm and large carburetor and are to run with SI carburetor again.

SI layout is retained: Air filter, sump and hose routing are still based on the SI principle.

Realistic expectation: If the set is mounted on an intact rotary valve, it is primarily an alternative in the design - not automatically a performance upgrade.

Fit and space on the frame

When fitted, the carburettor sump sits approx. 20 mm higher, but also approx. 20 mm further forward. This geometry was deliberately chosen in the design of the MRP RACING set so that the carburettor sump cover does not typically touch the frame when fitted.

Frame clearance: Tub position moves upwards and forwards - usually more relaxed than with solutions without offset forwards.

Attachment parts: The intake hose to the frame and standard attachments can usually continue to be used as usual (check depending on the vehicle).

Practical tip: Dry fit the tray, cover and frame spacer once before final assembly.

Important notes

Separate lubric ation: Separate lubrication cannot be used with this set.

Sealing surface: Suitable for short and long sealing surfaces of housings that were originally designed as rotary vane housings.

Large milled inlet: The set is designed for the small sealing surface, the lower part can be machined further if necessary to make better use of the available cross-section.

Vary motors: For mixed assemblies and heavily machined housings, always check the sealing pattern and contact surfaces.

Suitable for

Show vehicle and housing list

Vespa Largeframe (examples)

Vespa VNA and VNB

Vespa VBB and VBC

Vespa GT, GTR, Sprint

Vespa Rally

Vespa PX and T5

Vespa Cosa

Engine housing / base (short and long sealing surface)

Piaggio rotary valve housing (short and long sealing surface)

LML housing, if originally rotary valve base

Malossi, Pinasco housing, if rotary valve base

Note: The sealing surface and the housing base (rotary valve origin) are decisive. In the case of heavily machined inlets, special sumps or frame/motor combinations, please check the mounting position and clearance in advance.

FAQ

Does the housing have to be milled?

Generally not: The set is designed as a plug-and-play solution. In the case of very heavily machined inlets, an adjustment may be advisable in order to make optimum use of the available cross-section.

Does the set automatically provide more power on an intact rotary valve?

Not automatically. The main benefit is the repair and conversion option. The setup (cylinder, exhaust, carburetor tuning and intake condition) determines how the engine behaves in the end.

Can I continue to use separate lubrication?

No. Separate lubrication cannot be used with this set.

Conclusion

The MRP RACING diaphragm intake manifold under SI (MRP844) is a well thought-out solution for rebuilding large-frame engines with a defective rotary valve or converting a diaphragm back to SI basis. The design offset (higher and further forward) helps to position the carburettor bowl in a typically frame-friendly manner.