Pilot screw help NC30 1989
Posted: Mon Feb 16, 2026 7:34 pm
Having issues with a hanging idle after I adjusted the pilot screws as the bike was running hot. It has an aftermarket tyga exhaust and the pilot screws were set to 1 3/4 turns out. Bike idled and revved fine at 1 3/4 turns. But I went for a run and the bike stalled on idle and the temperature went up to 90°C The thermostat is brand new along with new o rings. So I adjusted the pilots after purchasing 450mm screwdrivers to reach the screws. And now she fires up straight away, but the idle hangs. When I spray the screws with penetrating oil, things improve albeit briefly. I have also checked the carburettor inlet manifold rubbers and they are fine. Im thinking new O rings on the pilot screws and check that the washers are the correct way around. Does anyone know what size the O rings are? And also what size the washers are, in case they are missing. Before I bought the bike, the carbs were supposedly serviced and balanced. But they weren't seated correctly before I removed them. So i don't hold much hope of the screws being complete. I have tried to give as much info as possible. Any advice is gratefully recieved.