my m8 bought a 17.5 carb for his 50cc skp we fitted it and the bike wouldnt start we put a drip of fuel down the inlet and got her going but it ran like shit and took 5seconds to build enough revs to pull away. it accelerated on/of up to 20 and then went better than before upto 40 . so then we swaped the 78 jet for a 62 for somthing to do and it wouldnt go atall so we put the 78 back it but it wouldnt start unless you drip fuel down the inlet. then it idles for a minute the rapidly revs up and flies off. we now its the jet but dont know where to start its gota standard filter and i cant find out what size jet to start with after reading loads of topics. am i right thinking a bigger jet for more fuel because its mixing with more air than before?????? we play with the mixture but put it back to factory cause it didnt make a difference
starting issues are fuck all to do with the main jet... its the idle mix. probably a shitty fuel tap and the float pin has come out of place. are all the pipes on correctly? could be a missing pipe/air leek wich would lean the fuck out of the idle mixture meaning it wont run. if the bike is stock put the needle on the top notch, a 53/56 jet, idle mix 1 and 3/4 turns out. im guessing it has an air filter? dump it and run the airbox.. filters do FUCK ALL but use more fuel and loose performance
cheers today we got it started and played with the mixture and got it running best we could after riding it for awile it is perfect and starts fine and runs better than ever. bit of a strange one lol
