I have many years experience of restoring and working a a wide range of bikes, but am struggling with a problem. Help Please. My Granddaughter has acquire a 1984 Honda Melody Deluxe with an ND50 engine and therefore the bimetal strip choke control unit. The engine was refusing to start, which I assumed to be a problem with the Choke unit, as it started easily with a shot of Easy Start. It now runs poorly, refusing to pick up engine speed when opening the throttle, but when I block the carburettor vent pipe with my finger it revs readily. I cannot find a fault. Help Please.
Blocking the vent pipe with your finger is effectively restricting the air flow which indicates it's getting too much air. It could be that the carb is worn out internally on a bike of that age.
Thanks for your reply. My problem in agreeing with you, is that the vent pipe communicates directly with the float chamber and nowhere else that i can find. I have dropped the needle a couple of notches , which has improved the running, but still not quite right. I think you are right in that the carb is worn out. I'm trying to source a jet replacement set but no luck so far.
You'd never find a replacement jet 'set' for that I think.........I may be wrong......... Search the carb number and make, then look on somewhere like NRP carbs. Or if you can determine the thread sizes on the pilot and main jets you can easily get replacements online that way; and probably the easier way. There is more than likely a replacement chinese made carb for it that be nearly as cheap as the jets
