engine when very hot with pmo carbs will run to red line. can stop only by cutting off ignition.
Your throttle cable or linkage is hanging up. On the drivers side in the rear where the transmission bolts up to the engine, there is linage that often sticks. Crawl underneath with a can of WD40 and clean or even bend the linkage while someone moves the linkage with the gas pedal. Also lube all linage at the carbs.
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