The American Revolution took place under much more favorable circumstances.
First, the American Revolution took place just before the Industrial Revolution (when colonial arms were as good as British arms). The Indian Revolution took place well into the Industrial Revolution (when home country arms were potentially much better).
The Americans had a higher standard of living that the British in 1776, and the American Revolution was fought largely to protect that standard of living. In their book, Generations, William Strauss and Neil Howe pointed out that American kids had far better childhood nutrition, and the average Continental soldier was two inches taller than the average Redcoat. The average Indian and a lower standard of living, and was shorter than the British. Also, American literacy rates compared favorably to Britain; Indian rates did not.
The American Revolution involved 13 out of 14 or 15 colonies (depending on whether you count Canada as one or two colonies. The Indian revolution was fairly localized to the northern and western parts of the country. it did not involve most or all of the sub-Continent. Specifically, the southern and eastern areas around Bombay, Calcutta, and Madras did not participate.
The American Revolution took place before the (Napoleonic-inspired) Concert of Europe. European countries were rivals, meaning that the Americans could find European allies. The Indian Revolution took place at a time when the Europeans were moving toward being "fellow" colonialists, and amicably resolving disputes between themselves, in opposition to Asian and African nations.