[blaisecardoz]

I was planing to fit in a K&N Filter for Royal Enfield Electra 5s, can someone tell me how to tune the carburetor, also will this change effect for fuel efficiency, also iridium spark plug will make any difference....

[barenekd]

The air filter shouldn't make any significant changes to your carburetion. Be careful about overoiling the filter, though. That could make it seem richer.
The iridium plug isn't necessary, just make sure the heat range on the plug you have are correct.
Bare