A riding buddy of mine owns a Bajaj Chetak. He took it to a shop to fix an issue of it not shifting, which ended up being a clutch cable replacement and gear cable. (If my terminology is correct)
The shop kept the bike for like a month and he gave them lip about having it so long. They said "Oh sorry" He said he'd go somewhere else next time.
So now it runs really slow. Lacking much power. I helped him change the oil and spark plug as basic maintenance, but I don't know whats up with the power or how to help him.
Any advice?