Welcome-Don't have one of your karts but---Use this link to find your belt by measurement :
http://www.*****************/tcbelts.htm
@ the top of the page on the link it has a belt chart also if you can't find the one needed. After you get the length needed you can forget about trying to find the manufacturers part numbered stuff!!
Once you get your belt # from the chart then you can search for the best price somewhere else if you want too.
(I found our belts for about $12.-$19. each + shipping)