so today i fitted my dellorto 22 phvb carb on my aerox 70cc, and am having a little bit of trouble, when idling, if i pull the throttle back quick, sometimes it will bog down and cut out although if i pull the throttle back slower its fine, also it seems to want to cut out and bog down more when the bike is warmer... this is only on low revs!! i can't work out whether this is jetting, or the air screw is in the wrong place, how many full turns out should the air screw be ? i'm currently usign a 95 main jet, i tried a 110 and it just splutterd all over the place.. but as i say it only bogs down and cuts when i try to accelerate fast from idle speed. if it helps im using an open filter and on my standard 12mm carb the jet was a 101. any help appreciated, thanks.
ye sounds like its the jetting, try putting your mixture screw at 1.5 screw out then see how it goes. also get a new plug and try go for a ride on it then take the spark plug out an check the couler if its black its running to rich wich i think is your problem. also get hold of some more jets
pilot jetting or mixture screw settings is where i would start, your main jet will only come into things above half throttle to full throttle so leave that until you sort out the bottom end. midrange is normally needle position, needle itself or could even be emulsion tube. unfortunately, bolting on a bigger carb is just the starting point!! ive not messed around with bigger carbs on newer stuff, maybe someone else can answer this one........22mm seems a big jump to me??
