As you may know I recently bought a Vivacity for my son and it was starting and running terribly. Anyway I stripped the carb, cleaned it out and replaced the jets etc and also replaced the plug. Air filter etc were fine and this past week it has run perfectly. This morning my lad messaged me to say it wasn't behaving, dying at the lights, headlight fading. When running he said it was fine. Could this be a battery issue possibly?? The battery is so far untested and I not sure how a duff battery would affect the running??
dying at the lights could indicate fuel starvation at tickover. Try raising the carb slide needle one notch, i.e, put the circlip on the next slot down.
Well my first thought was to raise the tickover anyway but I don't think the carb on this bike has that adjustment on it
Yeah I bought the D shaped driver for it but in any case I replaced the mixture screw when I stripped and cleaned the carb. I set it back to factory, do you think the mixture could be the issue??
Try the needle clip first. Then if its still a little off, turn the idle screw in a little bit.could be idling too low
Update from my lad, he's just phoned me now, bike got him to work, went out for his dinner, it started no problem and was running fine, gone to come back and won't start at all, currently pushing it back to work!!
Just got it home now, I think it might be the mixture is too rich. The bike has to be revved constantly to keep it running and a low revs it's stuttering as if it's choked up. Now do I screw it in to weaken the mixture??
Errr without looking I cant remember. Turn the idle screw in a bit maybe? They go hand in hand. I think its a mixture screw and not an air screw. So screwing in makes it leaner
Just on my way out now so will have a proper look at it tomorrow. When I did the carb it was running like a dream, 1 week later it's like this, can't think what else it could be. Will report back tomorrow
It was a very loose fitting if I remember, I'll check it and if necessary put the old one back in with a bit of mild thread lock
So I got to look at the bike tonight, removed the air filter cover and found that the mixture screw had turned itself in completely, that answers why it wouldn't run properly and died. (It also answers the question of why I had a spare spring when I rebuilt the carb!!) Oops! Anyway removed the screw, replaced the spring, set the mixture and hey presto it's running like a dream again!! Thanks for the help again chaps
