Stage6 Cylinder Kit 70cc Racing MK2 Aprilia SR50R.
The successor of the successful Stage6 70cc racing cylinder is called Stage6 Racing MKII 70cc and was completely redesigned for even better out of the box performance.
The cylinder with high-strength hard chrome bore plating was completely redesigned. A new transfer port design (6 instead of 5 ports) improves cylinder filling. The piston is no longer flat but domed, with a 0.8 mm thick piston ring to optimise performance and improve heat dissipation. Thermal properties were improved in all areas. Generous flushing of the bridged exhaust port; a pentagonal design and internal cooling ribs; one-piece head with cast scavenging canals – to name but a few of the improvements. Port timings are 190°-130°.
The cylinder yields 2 to 3 hp more power than the MK1, between 17-19 hp, without any additional modifications and in combination with the corresponding components. There is enough material for further modifications to get the cylinder above 20 hp. Definitely one of the most powerful 70cc kits on the market!
We recommend using a reinforced crankshaft, a min. 21mm carburetor and a racing exhaust to exploit the full power of this tuning cylinder..
The kit includes.
- aluminium cylinder, 47.6mm bore
- 1-ring piston with 12mm piston pin
- one-piece cylinder head
- gasket set
We recommend to clean the engine before assembly, check the condition of all components and use a new spark plug and new small end bearing. Do not forget to change your carburetor settings if necessary.
Squish clearance should be between 0.75 and 0.85. The cylinder should be run in for approx. 300 km with a 1:33 mixture to improve robustness and life expectancy.
– Original exhausts cannot be mounted with this cylinder.
– The temperature sensor (including thread) may not be longer than 18mm, otherwise it may knock against the cylinder head.