Hi Coopers, welcome to Outdoorking.
That Tecumseh Ultima (to Victa) or Vector (to everyone else) engine is prone to carburetor problems, but they usually just add up to it having accumulated some gum, which most carburetors do when run on modern fuel. Your symptoms (mainly, the engine hunts, or has cyclic changes in speed, with a cycle time of a few seconds) are almost certainly associated with lean mixture. It is likely that cleaning the carburetor carefully with carburetor cleaner will overcome your problem. It is important not to expose the plastic parts to the carburetor cleaner for long periods, though: spray the parts until they are clean then wash them in petrol. Do not soak any plastic part in carburetor cleaner.
Having said that, many people find that carburetor difficult to work on. Parts are less available than for some other engines, but most of them can be obtained.
