The thunderbird was first introduced in 2002 with a 350 cc AVL lean burn aluminium engine and a five-speed gearbox with the gear shifter on the left side.

It is also the first Royal Enfield to be fitted with a constant vacuum MIKUNI-UCAL Carburettor in stock condition from the company.

The 4-speed AVL aluminum engines with right side gear shifter were produced from 2000 to 2002 (approx less than 2 years), where as, the 5-speed AVL aluminum engines with left side gear shifter were produced from 2002 to 2009 (approx less than 7 years).

The Royal Enfield Electra, Machismo and Thunderbird all would later share the same 5-speed AVL engine 2002 onward till 2009.

Due to TCI the bikes would require a Battery to start in company stock condition.

The final drive chain is moved to the right side and it is the most obvious change from the old model apart from the new engine.

The fuel tank, mudguards along with seat, Meter-set, Handlebars, Pillion backrest, Headlight, signal lights, Foot pegs etc.

[1][2] It features front and rear disc brakes, a 20 L (4.4 imp gal; 5.3 US gal) teardrop shaped fuel tank, a split seat, digital speedometer console and fuel gauge, projector headlamps, LED tail lights and various cosmetic improvements over the 350 cc.