In need of some technical assistance or suggestions. Simply put the engine runs rich and it's fouling out the plugs. Is there something I should look for on the carb that makes it run rich? Air intake is clear & air filter is new. How much is an carb overhaul kit and about how much does it cost?
Could be a number of things. May are may not be the carb. Check you compression should be around 180 / 200 psi somewhere in that range. Test each cylinder for fire. Pull each plug wire and see if you notice it stumble. Rings? Valves? Choke sticking? Vacuum hoses leaking? I'd try running some Sea Foam though fuel system. When you start it cold does it start easy or tries to flood out? Most Daihatsu's Ive had dont like fuel when starting. No fuel and turn the key if using every day. If any, half a pump on gas pedal after sitting a couple of days. When running truck run it the upper end. These little engines like a bit more rpms.