yes, carb needs to be retuned once in a while coz the setting will 'lari' after harsh knocks and vibrations driving on roads....

yes, u need to retune ur carb after ur air filter upgrade... coz more air will enter, ur AFR mixture will be lean... thus, need to recalibrate the AFR.....

some claim that plugs/cable upgrades need to retune carb.... but whatever it is, it is still recommended to retune it after sometime.... even if no upgrades are done....

as ur problem with vpower.... i'm not too sure, but mayb because our engines dont need such high octane rating fuel.... i havent tried vpower yet (no money mah), but normal unleaded fuel works fine for me.... usually, new JDM or continental cars need higher octane fuel to maximize engine performance, but since we are using engines from 80s century, no need vpower lah.....


jz my 2 cents...

i retune my carb (AFR n idle rpm) and ignition timing for 10bucks only.... few months retune once.... or when ignition timing out adi, go retune...

usually my ignition timing will out first compare to AFR....

actually retune carb can diy.... only AFR abit hard, coz this needs experience and loads of trial n error.... idle rpm is easier to tune...

err... i'm in malacca... so, i tune in malacca....
if ur car stock standard, i believe many workshop also can tune ur carburettor.... its jz that they do a good job and charge expensive or not... as for mine, his tuning is jz ok wise, price is below average....