Hi I have 1998 yamaha yn50. Im just trying to get a starting point for my main jet size. I dont know whats been done in the past to it. I have read many threads about the standard jet size and now am quite confused. Im hoping someones knowledge may be able to help me. Ive read a 72 (which is on it now), a 78 and also back down the scale to a 55?? It has a phbn 12mm carb. Any help would be appreciated. Thanks in advance
Ideal mate thanks for reply. Gives me a starting point. Makes sense now as the airbox wasnt on when i bought it so previous owner must of up jetted. Take it running too rich also causes bogging down due to flooding?
Your bike has the same engine (Minarelli) and similar carb 12mm As my bike. I have a sport pipe I’m using a 68 and if I remember correctly it was a 62 standard so give a go see how you get on but put the standard air box back first
