best carb to use for super rat 66cc

hi guys i just purchased a super rat 66cc engine it has no carb so im wondering if my little NT carb i used on my now deceased 66cc china girl engine will be ok for it? or should i go all out and buy a dellorto sha 16.16 or is that too big? im only young so im not very experienced at picking carb sizes. also want to get a reed valve from arrowmotorizedcycles.com as the reed valve off my china is the wrong bolt pattern.

sweet as, yeah it is in pretty good condition the motor was running perfectly but started losing power and just got slower and slower so i ordered the super rat and took the old china girl of and pulled her down turns out the oil seal had failed on the clutch side an had greased up my clutch pretty good so got a full gasket kit and im upgrading all the bearings ill rebuild it slowly and mount it to my little bro's bike once done then i will give him my NT carb and buy myself a dellorto. any suggestion as to size? is a 16.16 too big? on my old set up at wot it would 4 stroke at the upper 2000rpm but if i leaned it out one clip on the needle my plug would turn white so i just had to live with the 4 stroking. i thought maybe a larger carb would combat the problem?