I got a honda cbr 125r 2010 4t and it was time oil change but i also wanted to clean the sieve?

So i drained the old oil i removed the parts i had to cleaned the sieve put it back all as it was i checked twice i put the new oil in heated the engine a bit waited put one more bit oil in and it should bebready to go but for sone reason the bike is slower up hill like its lazier and it has a hard time falling into second geqr anyone know wtf

Eh