Leave the radiator cap off it and let it get to what should be operating temperature. If you don't see coolant flow through the cap fill hole, the pump may have failed. If it's dying when it should be hot and you're sure the pump is pushing water around the block and through the radiator, check the auto choke on the carb. If the choke butterfly is still closed, the auto choke has failed or needs adjusting. Check the condition of your plugs as George has suggested as this is an indicator of a running rich issue which has to be fuel as a primary fault, or ignition as a secondary (poor tune, big plug gaps, tired coil...) If the timing chain is noisy, I'd put a kit through it or if the engine has done a ton of miles and you're pretty sure the chains and guides haven't been touched, I'd think about doing it. These aren't interference heads so if you jump the timing it won't damage the valves, but a busted guide or chain will really make a mess in the front of the engine (you don't want to drop the sump to fish out fragments of metal and broken guides)