Vespa ET4 main jet question

I've upgraded Vespa XL50 4T to 79cc cilinder. Should i change main jet to? If so, which would fit the best?

Carburettor is Kehin CVK 18.

hi,

 

more cc needs more food;-)

 

use this sets :

http://www.sip-scootershop.com/DE/Products/KODB0010/Dusenset+KOSOKEIHIN+10+Stck.aspx

http://www.sip-scootershop.com/DE/Products/KODC0010/Dusenset+KOSOKEIHIN+10+Stck.aspx

 

 

regards

 

 

Thanks for responce :) but those dosent look like my ones. My main jet is 5x7mm... very small :) It's numer 78. Witch numbers should i try ?

Thank you :)