Hi, I'd just like to add that I have read the guides and I can't find the answer I am looking for. I have an aerox with a 70 kit in it and I fitted a Mikuni 20.5mm carb to it. The main jet fuelling is perfect but it's idling too fast. It is running the stock mikuni pilot jet in it. I tried to slow the idle down using the idle speed screw and turning it out but I get to the end of the threads with the idle still being slightly to much. When I screw the air screw out it speeds the idle up! Any help greatly appreciated Tam
Seems to be! The throttle cable did seem a bit tight to get on? Theres plenty of free play at the handle bars though. Thanks Tam
if it has a thorttle splitter it can have slack at throttle end but still be high at carb end (most have a split cable for the oil pump obv) try and listen for the slide hitting the idle screw when you come off the throtle quickly.. its hard to explain, if your atall unsure just take the cable out, it will run. set the idle sped in fairly high, now wind the idle mix screw all the way in... now, wind the screw out one and a half full turns from fully in (rough setting it should be at) if your idle mix screw is filter side of the slide (rear of the carb) then its an air screw, if its inlet side (front of the carb) or "ahead" of the slide then its a fuel screw.... basicly, this control's wether winding out or in is rich or lean respectivly.. ok, start the bike... it will idle high, this is fine, wind the screw outwards half a turn at a time, pip the thorttle, when you go in a leaner direction the revs will rise, go quite tinny and you will get a delay/stutter when you quickly pip the thortle to over half way from idle.. pip the throttle and let it settle... now, when you move in a rich direction you will drop the revs off, the tone will go down and when you quickly snap the throttle to past half it will "bog" or delay while makeing a wet BRRRRRRRRRuuuuuuummmmm noise... now, here lies a problem, its hard to tell when the revs go up as its ideling fast, and most bikes will untill you set them. so do the opposit, try and kill off the revs slightly, then once you have the revs dropping off slightly and can pip the throttle past half wiht no hickups delays or bogs then its set and you should be able to wind down the idle speed...IF for this the idle mix screw needs to be any further than half out or any further than 3 full turns out (wich i assume is the case) then you have to alter the main jet size... this is usually aparent as if you have a fuel screw (screw is inlet side of the slide) and it needs to be wound out past 3 full tuirns out your not getting enough fuel, so need a bigger jet, the same is for the opposit direction, and they are opposit for an air screw... if that makes sence , ima make it easy for you tho, you probably need a richer pilot jet and probably a smaller cutaway in your slide.. but experiment away... if you get stuck dont be afraid to ask again.... you dont have to say it for me to know its not coverd often i quite enjoyed writing this one
Great advice mate. Your a wizard. Thanks. Problem is that its a mikuni 20.5 and pilot jets are impossible to find. Both screws are on the airbox side on this one. Not to hijack the thread but I was going to fit a stage 6 pro rep pipe instead of my turbokit pipe. Wise move?? I've heard mixed reviews.
Also, It's running a 86.5 mainjet. I ordered a 95 to try and sort this problem. After full throttle with a plug chop the plug is perfect though? Tam
by "side" i mean front or back of the carb not left or right.... evedently its obviously hard to explain wihtout a picture. as for mikuni jets being impossible to find, did you acxtually TRY phoning a mikuni stockist? http://www.allensperformance.co.uk have it all in stock
Yea I have done some research but it hadn't came across these guys. I am from Northern Ireland so I'd never heard of them. I'll give them a call in the morning. Thanks for your help and patience :cheers: Tam
