dellorto SHA clone carb help

[ipwnr]

ok i purchased a dellorto SHA clone carb off of ebay http://www.ebay.ca/itm/Performance-Carburetor-Air-Filter-Assembly-47cc-49cc-Pocket-Mini-Bike-Carb-CA42-/180799753465?pt=Motorcycles_Parts_Accessories&hash=item2a18814cf9#ht_1841wt_985 and when i put it on my bike (66cc china girl engine) it felt slower like the acceleration was perfect but when i started to hit 30-35kmh+ it was 4 stroking a lot and but idle perfectly and i asked the seller about the jet and he said it was a 65 and I'm not sure what jet size i need for it because with the stock carb i would be able to get to 50-53kmh but with this i only got 45 kmh max.

 

[Rocksolidperson]

The 4 stroking is caused by an over rich mixture leaning it out to a point where it stops 4 stroking is normally the sweet spot for these motors, you can try raising the c=clip on the needle a notch or two OR if the carb the same as the one on my build here
: http://www.youtube.com/watch?v=789X9lHJ-iI

then turn the brass mixture screw in at 1/4 turns at a time untill the 4 stroking stops.

 

[ipwnr]

thanks for the reply but i already fixed it , you were right about the rich mixture i took the jet out of the stock carb and i used teflon tape around the threads of the jet so it would fit the new carb o and i forgot to mention its actually a clone with no idle mixture screw.