uhoh!
Don't tell me the kart is stamped with
www.jbkart.com 
if so I really hope you have the rest of the frontend, otherwise you'll be in trouble...
jbkart is out of business, parts are no longer available,
and for all I know all these adjustable casters are made specifically for a certain chassis
(at least mfg) So the tecno doesn't fit on a buller and vice versa, etc..
IDK whoelse made such adjustable caster setup tbh, and I'm afraid I can't be of much help there in case you don't have the front axle complete.
IDK.. tough if you don't have it complete,
making the adjusters is not trivial either I'm afraid,
they need to be precise and perfectly identical mirrors of each other...
that alone requires some skill, but they also must end up within a specific range of caster (10°-15° usually)
And what's worse at the correct camber and kingpin inclination
or the kart will handle less than optimal.
it was a concession kart which is partly a good thing
(means it's relatively sturdy at the price of being heavy)
also it's MEANT to take a 4stroke enigne of the industrial type, which makes it very convenient to mount your gx200 clone without any issues.
it should be a hair larger than your ordinary race chassis too, so it's a bit more convenient to drive
'sid
