While there are several causes of overheating, the two most common reasons, by far, would be a damaged or worn water pump, and or a faulty thermostat(s).
No gas?
Engine surging is usually due to a fuel restriction. Troubleshooting starts at the fuel tank pick-up tube, and all connections, check valves, and components all the way to, and including, the carburetors.
It's the current flowing in a wire that causes it to overheat.
sounds like your only running on one cyl
friction
friction
An outboard surging condition is usually due to fuel starvation. The fuel tank, hose / connectors, primer bulb, and or filter(s) are all suspect, and should be checked. Also possible, carburetors and fuel pump.
Dirt, moisture and overheat
what causes a Honda CRV to over heat
Head Gasket to replace
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Air inside engine