Yamaha Aerox 50cc acceleration problems

I have a 2010 Yamaha Aerox I replaced the standard bore for a malossi 50cc street race kit it's got 2 extra ports in the bore. It was running fine before I changed the bore.
For some reason after replacing the bore and running it in I finally decided to give it a proper try.
For some reason I have no power at all I got 3.7 gram rollers and yellow clutch springs.
The only time the power would kick in was when I hit 40mph n it went crazy to 70-75 mph
Driving me crazy can't pull away on hills
Also put a stronger contra Spring. So I changed the clutch springs to malossi red.
Worse pull off but now the power band kicks in at 30mph I have upjetted played with the needle
It runs best with the needed clip at the top
Anywhere else it spits and splutters
Also would like to ad 1st start in the morning it pulls off like a rocket I mean mental for a 50cc
Then after that it's terrible n I mean bad.
Does anyone have any ideas at all will help loads thank you for taking you time to read my advert
I will add a photo of the cylinder kit
Note this is still a 50cc not a 70cc

 

Sorry for no reply feel for you

 

I have the same problem if its fixed can you please help me too?

 

What are your probomems