so posted motorcycle to cars,moved you to Yamahammer.
no year I guessed at the move, so none known and matters.
2008 to 10 says wiki.
top cause all machines with engines (fuel) and not driven every day
the fuel goes bad. and clogged filters and injector. 1here
the battery bad,or charging system weak
if goes weak spark fails, EFI must have 13 to 15vdc at all times running, if not EFI fails, (electronics for spark and fuel)
most motorcycle sit parked for endless months.or years.
for sure in the rust belt, nobody drives on ICE
same with garden tools sat idle and fuel is now junk.
the word is MISFIRING< due the 3 classic causes auto cycle engines for 100years
bad fuel is first due to not driven daily!!!
this is physics based and ASE rules of testing not guessing.
using tools.
1: bad compression on the 1 cylinder? over 150psi a must.
2: bad spark on this cylinder, . spark plug bad. or coil or spark trigger devices.
3: bad fueling or bad fuel. under or overfueled or leaking injectors
Is a single cylinder engine, V1 is 2008 to 2010 seen in India
are you in India. we are USA>?
Yamaha YZF-R15 v1.
as seen here.
https://en.wikipedia.org/wiki/Yamaha_YZF-R15
why leave off makers name and YZF, do you want lies.?
I say get the Motorcycle serviced in a real shop ,they have to tools and the skills to find the cause.