Yesterday had the work done. There is no noise of big ends now. The ones came out were worn out from the inside. The 'main' was not replaced as mechanic said it was fine and it was set correctly by him. He was saying that if you ignored the big ends sound, there would have been alot of issue with the engine in near future resulting in engine change.
Also, please comment on mechanics statement that in case of issues its not worthwile to overhaul a liana's engine and changing one is the best option.
The new big ends are attached as per picture.