Due to the completely new designed intake system and the massive construction of the engine housing, it is possible to use much more powerful 2-stroke foreign cylinders.
The air-cooled engine block was prepared for a very cheap and robust 230ccm cylinder. Plug and Play this combination delivers about 30 HP at 30 NM (!!). By modification of this cylinder, performances over 50hp at 45 NM are possible.
More details on request.

( KR0022 )

All possible piston sizes for tuning Vespa smallframes are available in the motobike catalogue. The only gap was to be found at 60mm bore.

But this gap is now closed by the Overrev 60mm piston - it is a highend replacement for the Rotax Polini piston.

Manufactured by Wössner in Germany, this piston is a masterpiece. It has only one piston ring with its location pin in the middle of the boostport. This piston is a superb upgrade for any Parmakit Wforce, Quattrini M160, Polini Rotax, Falc 60 cylinder and sure will be the basis for a few tuning projects.

A specialitiy about this piston: The delivery scope contains two wristpins. A light and short pin and a longer, heavier version. The piston has two clip grooves each side - for the shot pin, you are using the inner grooves, for the longer pin you will use the outer grooves. The idea is, to change the balancing factor of the crankshaft with very little measure.

Ring position: 90° to the piston pin (central over the inlet)

Piston pin: 15mm

Compression height: 29mm

Piston dome height: 3mm

Piston length (without dome height):  64.5mm

Exact diameter: 59.94mm

Piston pin length: 45mm und 50mm

Weight, with the short pin: 199g

Weight, with the longer pin: 205g

(KR0068)

Suitable for internal and external shaft seals, this drive shaft is designed for rear wheel torques of over 500 Nm, especially for the powerful BFA's and M244. However, it is important to make sure that the shock absorber can cope with the torque applied. The increase in strength was achieved by enlarging the bearing journal to 25mm.
The complete set, as shown in the pictures, is delivered.
The steel ring is inserted under the bearing, then the bearing is installed in the engine block. The rear wheel nut is a nut with M16 x 1.5, the original nut cannot be used.
ATTENTION Observe tightening torque: 110Nm
The original basket for the nut must be used! We recommend additionally some Loctite medium strong, also on the polygon.
Make sure that the shifting bolt does not protrude more than 1.5mm over the shifting cross.

(KR0070)

( KR0045 )

( KR0017)

( KR0046 )

The suitable brake drum for our polygon main shafts.
All brake drums sold by us are individually x-rayed before processing, as the quality of accessories is known to vary greatly. This is the only way to ensure that there are no material defects which could lead to material breakage in very powerful motors.
Bases for our drums is the piaggio drum.
Within the DIN tolerances, the drum goes slightly tighter than usual on the polygon shaft.

 (KR0025)

Hard Facts:

• CNC turned
• CNC milled
• CNC ground gears
• 0,9 mm hardened
• Auxiliary shaft two-piece
• Gearbox surface compacted
• 25% higher strength in 3rd gear

Original gearbox PX200:
1. gear: 12:57; 2. gear: 13:42; 3. gear: 17:38; 4. gear: 21:35
In 4th gear at 8000 rpm with 3.50-10" the speed is 133,2 km/h.

KR gearbox:
1. gear: 12:56; 2% longer; 2. gear: 11:34; 4,5% longer; 3. gear: 17:37; 2,7% longer; 4. gear: 19:31; 2,2% longer;
In 4th gear at 8000 rpm with 3.50-10" the speed is 136,1 km/h.

ue to the reduced profile shift, significantly higher strengths could be achieved.
It must be explicitly ensured that the axial gear backlash is set to 2-4/10 mm during installation.
Background: The contact surfaces of the gears are larger than in the original, which reduces the tilt. If the backlash is set too low, there may be a lot of friction, the vehicle "pushes" forward already in idle speed and shifts very choppy.
Compared to the original transmission the following higher strengths have been realized:
1st gear: +26%; 2nd gear: +29%; 3rd gear: +25%; 4th gear: +38

(KR0015)

The KR CNC shift key comes around the corner with several new features.
- Richer detent points without using a stronger spring
- Form-fit connection between switching shaft and switching arm
- hardened switch arm
- replaceable hardened switch block
Who does not know it, at the top of the pass, no gear can be engaged, there is only a clattering in the gearbox and the cone pin has gone or the shift arm is broken. This can't happen anymore with this shift lever. Because of the form closure and the M4 screw with the strength 10.9 nothing will move there anymore. Safe and clean switching operations are guaranteed. The product for the long-distance driver who likes to change gears at will and who does not want to worry about the gear shift lever.

(KR0036)

The KR CNC shift key comes around the corner with several new features.
- Richer detent points without using a stronger spring
- Form-fit connection between switching shaft and switching arm
- hardened switch arm
- replaceable hardened switch block

- 1,5mm overhang to the sealing surface!!!
Who does not know it, at the top of the pass, no gear can be engaged, there is only a clattering in the gearbox and the cone pin has gone or the shift arm is broken. This can't happen anymore with this shift lever. Because of the form closure and the M4 screw with the strength 10.9 nothing will move there anymore. Safe and clean switching operations are guaranteed. The product for the long-distance driver who likes to change gears at will and who does not want to worry about the gear shift lever.
(KR0051)

( KR0047 )

This head is made for the 70mm Simonini  Mini Evo 2 Cylinder.
- 21ml @ 1.0mm squish equals 12:1 with 60mm stroke
- head protrudes 2.7mm in the cylinder
- 152mm outer diameter
- Omega combustion chamber for faster combustion
- central M14 spark plug
- additional drilled for cylinder removal from block without need to remove the head.

(KR0085)

Facts:
- No O-ring groove (this always breaks on the original head)
- Torroid combustion chamber
- Compression volume is 26.6ml at 1.3mm QK -> This is a compression ratio of 12.5:1 (idea: same compression as BFA head, only with 1.3mm QK instead of the 1.8mm QK of the BFA)
- Ribs a little flatter than original (idea: save space, lower cap possible)
- Omega combustion chamber for faster combustion
- Additional cut-outs at the cylinder screw positions to allow the cylinder and head to be removed
(KR0090)