The bike, parked without others outside a five-floor apartment block in Patong's Soi Nanai 8, could not be saved.
Two other next to it were damaged but residents managed to shift other motorcycles from the blazing Honda Wave before they too went up in flames.
Patong police are inverstigating.
A spate of motorcycle fires earlier in the year destroyed or damaged many bikes along Phuket's holiday west coast.
The smell of fuel indicated that today's blaze could have been deliberately lit about 7.10am but other residents said they had noticed sparks shooting from a faulty electrical transformer.