How was the original carb acting? (was it surging and hunting or not running at all or????
Did you try just replacing the diaphragm on the original or do anything at all to try a fix?
Those pulsa jet carbs will sometimes come around with just little TLC type cleaning and new gaskets, diaphragms is why I ask. A rusty bad inside gas tank is not a good thing for those type carbs either.
What is the part numbers on the clone carb you installed?
I've installed (replaced those type carbs with clones) and never had to fight the governor linkages, so that might be a hint as to the wrong carb.
Also use two gaskets on the intake or use a permatex silcone sealant such as copper plus on the intake gasket and be sure and use a anchor bolt in the bottom of the gas tank support to the engine block or the carb will vibrate loose and break off a intake ear, but leak air first and surge.
Here is a link to give you a few hints about the carb for that 5 hp engine.
The replacement clone carb should have been for a 498298 Briggs carb.