i have started looking for a new engine after the axle damage.. i have some questions..

what are the differences between 5 ports and 3 ports engines?

also at novarossi you can see S and L engines, for instance mine was an LL5, what are the differences?

also something to note, i downloaded some documentation for an O.S. engine and it is much better than Novarossi documentation and for me this matter, although i don't have an opinion if they are better engines.