Modern Vespa

Hello all, I have a problem with oil in my air filter of my MP3 400, so i am thinking on maybe opening engine and swapping to 500 cylinder and piston, i have already read some things that if you put 460cc it is plug and play but idk if some remap is needed due bigger cylinder size, so if someone have experience it would be good to share.

As for the oil in filter happened last year one time after it was in service(then also hose to airbox was cracked and replaced), i thought maybe it was ovefiled drived it nothing. This year oil was also charged but it wasn't overfiled it already happened 2 times but a bit less than first time.

Be aware that Piaggio specs the wrong refill quantity

They spec 1,7Liter but actual is 1,5Liter

Using the 1,5 spec the oil level should sit at or just over the MIN line on the dipstick

I have read that somewhere, so you dont need to fill it up to max? First time it was on max maybe a bit over, that is why it filed up airbox, now oil was maybe in middle on dipstick but i can se oil already on front hose of airbox it didn't really goo all way to back window is still clear but I didn't opened airbox yet, first time it happened this year I noticed also saw oil on front hose then opened saw some on filter cleaned it all put it back now again. I will maybe buy endoskop camera to see if i can see anything tru sparkplug hole to see inside of the cylinder. Thanks for advices.