GY6 Big Bore Builds S-1 High Power Camshaft

High-Output Camshaft for GY6 4-Stroke Engines

The TFC Special S-1 High Angle Camshaft is built for GY6 engines with big-bore setups, specifically those running cylinder bores from 58.5mm to 63mm. It raises valve lift to 6mm, which allows more air and fuel to enter the engine and helps power build at higher RPM. It is one of the GY6 scooter parts you can use to get the most out of an upgraded engine.

Performance Characteristics

The S-1 uses a distinct profile designed for high-performance use. Its valves stay open longer and lift higher, which makes it a strong choice for riders who have fitted a big bore kit and want the most from it. For the best results, pair this cam with a high-flow cylinder head, a performance exhaust, and an upjetted carburetor.

Installation and Compatibility

The S-1 Camshaft works with GY6 QMI/QMJ 152/157 4-stroke engines that have been fitted with big bore cylinders. Keep in mind that this cam does not suit stock 57mm bore engines, since its aggressive lift profile is made for larger displacement builds. For strong results, avoid running it with a stock head and stock jetting, as those parts may limit the gains.

Specifications

• Cam Profile: TFC Special S-1 high angle
• Valve Lift: 6mm
• Intake Lobe Diameter: 26.75mm
• Exhaust Lobe Diameter: 26.35mm
• Cam Gear Teeth: 34
• Cam Bearing: 6002C3
• Model Fitment: 58.5mm–63mm cylinder bores
• Fits: GY6 QMI/QMJ 152/157 4-stroke engines (125cc/150cc) with 58.5mm to 63mm big bore cylinders

Fitment

Fits:

• GY6 QMI/QMJ 152/157 4-stroke engines (125cc/150cc) with 58.5mm to 63mm big bore cylinders

How to choose: Confirm your cylinder bore falls between 58.5mm and 63mm. This cam is not intended for stock 57mm bore engines.

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