By blanking the channels leading to the AIS (sometimes incorrectly referred to as EGR) valve and disconnecting the connecting hose, the valve is rendered inoperative. This not only increases the cleanliness of the engine, but also breaks the connection between the exhaust passages of the individual cylinders and they stop pressurising each other. Genuine Royal Enfield caps will replace the original caps with a hose connection (this can also be removed). As the original AIS valve remains in place and is still wired into the bike’s electronics, there is no risk of any error codes in the engine’s ECU.
Specified for EURO4 models (i.e. model years up to and including 2020). This kit cannot be used on EURO5 models (i.e. from model year 2021)!
Czech manufacture with emphasis on quality and original Royal Enfield caps.
Sold as one set (pair).
The AIS valve closes/connects the exhaust manifold to the intake manifold and allows clean air to flow from the intake to the exhaust (and vice versa), reducing the concentration of exhalations in proportion to the total amount of exhaust gases and allowing fuel residue to burn off. This bureaucratic nonsense carries with it negatives such as fouling of the system with exhaust gases and thus limited lifetime (then the check engine light comes on and you have to go to the workshop for diagnostics).
The caps/plugs, by their design, eliminate the function of connecting the intake and exhaust manifolds. The solution also prevents the individual cylinder pressures in the exhaust manifold from influencing the quality of the fresh mixture filling the cylinders and the idling stability. The elimination of “controlled” mixture burn-in in the exhaust (i.e. less frequent exhaust firing) results in a smoother flow of gases in the exhaust manifold and thus a smoother transition from deceleration to acceleration.