Jet -MIKUNI (type: VM11/22) VM- (52.5)

The main jet is considerably involved in the mixture preparation of the carburetor.
If it is too small, the engine dies off under full load and/or runs so leanly that the piston including cylinder overheats and a cylinder damage would be the consequence.

If it is too large, the mixture is too rich, the engine runs very unevenly and can only deliver a fraction of its possible power.
Here it is important to find the ideal compromise.

To determine the main jet, the engine is selected from the gut so large that the goal is a stuttering engine under full load. Of course you need some experience to do this, but a nozzle can be changed quickly. Once you have found such a nozzle, you mount a smaller nozzle until the engine does not stutter under full load anymore.

Mikuni produces carburettors for the original equipment on behalf of many vehicle manufacturers.

In the case of the Piaggio / Gilera 2-stroke cars from 125cc upwards, Mikuni used a VM carburettor which, in contrast to the nomenclature otherwise used by Mikuni, uses different nozzles than the other carburettors marked VM.

However, the height of the head is longer at Mikuni, which means that it is deeper into the fuel level of the float chamber.

• Head diameter: 8,0mm
• Thread: M6 x 0,75
• Total length: 10,5mm
• Thread length: 5,5mm
• Designation Mikuni: VM11/22
• 50 - 150 ( step 2,5 )

Used in:

• PIAGGIO: Skipper, SKR, TPH125, Hexagon
• GILERA: Runner 125-180

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