Over the last 3000km, my TVS Victor with 61.5K on the ODO has started showing certain symptoms of a problem I'm unable to get to. When the engine is warm enough and above 40kmph, on deceleration, I hear the exhaust 'pop' once in a while. Sometimes, the engine is idling just fine, but as soon as I increase throttle, the engine coughs and dies. This happening in peak hour traffic is a pain.

Spark plug changed, carb cleaned, air filter cleaned, problem continues.

One mechanic says 'need to adjust valves'. Another says 'common problem with TVS Victor, no harm to engine, forget it'. However, I can't live with this noise and stalling issue. I'm thinking this is either due to someone tampering the carb setting or the timing going haywire due to the engine getting older and cam chain getting loose or something along those lines.

Can you guys advice where I could start looking and if possible a link to help on adjusting carburetors and cam chains would be highly appreciated! I prefer doing stuff on my own as far as possible because mechanics don't seem to be bothered with any diagnostics around here, all they do is apply 'patches' to problems. Not how I do things!