Why not you try the Torco RCL (Racing Cylinder Lube)? I already try this additive. It's work.

TORCO RCL is specifically designed for high performance engines. It lubricates fuel lines, injectors, piston rings and valves to increase engine efficiency.

A combination of state-of-the-art fortifiers and additives provide protection under extreme temperature, high RPM and load conditions.

TORCO RCL promotes clean burning, improves throttle response, prevents pre-ignition, plug fouling and keeps valves clean.

This product is to be POURED into the PETROL TANK. One bottle of 500ml can last up to 04 TIMES WHEN YOU PUMP FULL TANK of PETROL.

The price is not so expensive, just RM30.