Kit 50cc liquid MALOSSI G2 Replica (G2R) aluminum MBK 51 / motobecane av10


The famous kit MALOSSI G2 REPLICA for MBK 51 liquid cooling, solid, torquey and powerful!

More details

manufacturers : MALOSSI

229,50 € 229.5 tax incl.

Availability: At home in 2 to 5 days

This kit G2 replica is the copy of the GR2 real, obviously much less powerful than the real one of competition! The real competition GR2 (G2) has a piston forged in mono segment, an exhaust bar, track digrammes ...

This kit being a copy made for the road is more solid, the barrel escapement has been replaced by normal exhaust, the exhaust thread is no longer for big ball of 38 but for common ball joint, the piston is a bi model hard chromed segment convex, this bi segment slowed amply the high speed and promotes torque, the wear is much less lively.

The piston is slightly reopened on the back to facilitate the sweeping. It is identical to the G1 replica but in liquid cooling, which provides additional security of power and strength in addition. The cylinder is high-end aluminum and treated nykasil, the bore is 39mm as the origin so it develops a displacement of 50cc, it has 6 transfers and a normal exhaust.

The or this kit is very significant is that it preserves the form of transfers to the base and the conduits of the real GR1 and GR2. So increased transfers on the front, this form really offers maximum performance, you will obviously have to align your housing to this kit . The cylinder head is a polished hemispherical, high-compression chamber, it is perfectly studied at cylinder / piston with a ratio of 11.8: 1.

This kit is really powerful, solid, it will offer you a very good couple and pretty good high diets, diagrams are well served. We will only regret that there are not several joints to perform the squish (you can ask the G2R / GR2 base seals)


Diagrams and technicalities:

Material: aluminum treated nykasil
Expected for stroke: 41,80mm (origin MBK 51)
Diameter: 39mm
Actual cylinder capacity: 49,93cc
Lightened MALOSSI model piston with internal cooling fin
Segment: 2 thick 1.5mm hard chrome domed for less friction
Transfers number: 6
Exhaust: normal width 100 °
Room volume 6.5ml (for 2.5ml long base already removed to measurements)
Hemispheric room (room Ø29)

Exhaust diagram: 184 °
Side admission diagram: 130 ° number 4
Rear intake diagrams: 117 ° number 2
Compression ratio: 11.8: 1
Tightening of the bolt advised to the dynamometer: 1,2kgm
Advance to ignition recommended with an electronic DUCATI on MBK 51 / av10 motobecane: 1.5mm before the top dead center
Recommended lapping time : 250km

View of the preparation carter to perform :


Tip: Mount the exhaust diagram at 188 ° to obtain excellent high speeds. In general we advise a side exhaust difference of 60 to 65 ° and this preparation will bring you closer ( D: 58 ° )! The exhaust opening angle is 100 ° so it is good but upgradeable to 105 ° and the shape is correct but can also be improved. The base is excellent and very worked, the finish is pretty good! An exhaust polishing and calotte piston cap also good.


We recommend it with at least : carburation 17,5mm minimum, reinforced bearings and crankshaft, racing exhaust, cold candle B9 for break-in / adjustment then B10 (especially with the advance of 1,5mm advised by malossi), preparation of the crankcases.

The pack contains :

Bi segment piston d.39mm

2 segments d.39mm

Piston pin Ø13mm

2 piston clips (shaft rods) in C d.13mm

Cylinder 6 transfers G2 replica aluminum d.39mm 50cc

High compression cylinder head

Complete seal pack




Spare parts :

O-ring pack of cylinder head

Pack seal others (base and breech paper, exhaust ...)


cylinder and piston without cylinder head

Ax + Clips

2 segments Ø39 by 1,5mm

Cylinder head

Piston clips in G

Optionally we offer a stage 1 preparation, this preparation is a modification of the exhaust port by increasing the diagrams and improving the pipe, it increases the performance of the cylinder. An improvement of the bottom of skirt is also included in this modification. Allow a little extra time for this preparation!


View of the prepared version:



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