Help increasing engine torque

i have a shineray xy125gy http://portsmouth.gumtree.com/postin...de.__big__.jpg
and the torque from it is shameful what can i use as a good few ways to increase the torque because into corners it feels like its gonna fall over someone please help i need more torque the bikes nice and easy into corners but just want the bike to feel a little more steady but i temporarily changed my carb for a 26mm molkt one from xian which seemed to increase the torque and did the job but starting was a major issue it just wouldnt
so ideally i would like that on and working however as i have this engine
http://www.lifan.com.cn/en/%5Cupfile...5C156FMI-A.jpg

where the manifold is and the carb inlet places the adjustments on the wrong side near the chassis so its a bit of a pain to set up
does anybody know where i can get a smaller manifold as this would put everything into easy access its a bolt on style carb
and also when xian have done there rear shock i want one so hope its soon but have had to resort back to my original carb which makes it ride bit shakier into corners so i am gagging to get it set up correctly any experiences with this carb thanks for any help
http://www.ahpminis.com/store/images/molkt26.jpg

in have a 17t front sprocket if i dropped to a 16 what would i achieve many thanks