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#P542
Stage6 Streetrace 70cc cylinder kit for Yamaha Aerox/ Minarelli 50cc horizontal liquid-cooled engines.
With the Stage 6 70cc Streetrace grey cast iron cylinder series, Stage6 offer a bargain version of the popular SportPro Aluminium cylinder. The cylinder is stamped 49cc
The transfer port layout has been adopted from the high-performing 70cc Stage 6 SportPro and slightly modified in order to fulfil the thermal demands of the cast iron cylinder. Stage6 have gone for a piston manufactured by the renowned Italian company Vertex Pistons.
The performance characteristics mainly correspond to those of the SportPro; a bit more power when accelerating coupled with 0.5 hp less peak power. The ideal rpm range is around 10,000 rpm. It is recommendable to use a 70cc sport exhaust system. When it comes to looks, the cylinder is unobtrusive and similar to the stock part.
A standard crankshaft can be used with these kits although we do recommend fitting an up-rated crankshaft like the Stage6 HPC. Match this kit with a Pro Replica exhaust, Sport Pro variator kit & 21mm carb for optimal performance.
This kit can be used with a 12mm oversize crank if this piston is used.
A BR9ES long reach plug is required!
10mm gudgeon pin.
Included:
cylinder, piston kit & gasket set.
Stage6 S6-7216651
Hi, the carb hoses are not used with this cylinder kit, the outlet is just a vent for manually bleeding the cooling system and nothing connects to it. The carb hoses are used on some standard bikes to warm the carb but are not used on performance kits and can be left open.
It will work fine and will rev fairly low which is quite safe for the engine but the performance would be substantially improved by fitted a more highly tuned exhaust such as a Stage6 Pro Replica
there is no set rule because the wear depends significantly on not just mileage but how high it is allowed to rev and how much load the engine is put under.
if you don't change the rings after they start to wear you start to loose compression and power.
I would probably replace the rings at approx 3000 miles- if you remove the old ring and push it down the bore with a piston you can tell how worn they are by the gap between where the ends of the piston ring almost meet (compare to a new one)- there should only be a hairs width gap and it will loose power noticeably by the time it gets to 1mm-2m
check also for gaps between the ring and the cylinder wall by holding the cylinder up to the light
