Ref: reducing oil consumption; clean valves and combustion chamber

[Rudolf]

I've managed to resolve the cylinder cheaply by purchasing a new genuine kymco piston with rings, pin, circlips, equivalent of 50$ and the old cylinder was honed with an electric drill operated honing device by a mechanic at the equivalent of 6$.... He removed and smoothened all of the scratches.

[windwheeler]

Nice.  this will resolve your problem!  You will get a good running GrandVista!

[Rudolf]

Also i've changed the timing chain because it was rattling at idle and noticed that it was stretched beyond the limit of the chain tensioner. The chain was flapping around and hitting inside the engine only at low RPM.




The bike before with the old timing chain:

The bike now with the new timing chain: