Hi Husky888 and a warm welcome to the forum.
It sounds as if your governor has packed up. The illustrated parts list shows 2 springs, one being the governor link spring which goes around the governor link rod, which connects the carby to the governor and the other being the governor spring which i have highlighted with a green in the image below.
Having said that the absence of the governor spring should not make your engine over-rev, in fact it should retard the throttle to idle, if the governor itself is working correctly. The role of the governor is to close throttle, the governor spring in turn opens throttle relative to the tension on the spring. i.e. move throttle lever to full revs, more tension on the spring, move throttle lever to idle position, less tension on the spring.
To check if the governor is functioning correctly, start the engine and move the governor lever so as the engine idles. if you let it go manifold vacuum will move the carby butterfly to the more favourable open position. You should feel a considerable amount of resistance on the linkage as you move it to the full throttle position(i.e. it should be pushing back to the idle position). I'm guessing you will feel no real resistance hence leading me to believe the governor has failed.
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Your governor gear part number is 494845 and has been discontinued, but there is 1 US based ebay seller who has 2 NOS ones available.