Spitting carb

Can anyone help ? A strange one I know but I have a 1965 LI 125 which I'm told has been bored out to a 225 (I don't think so) but she has a Dellorto PHBH30 carb with open bellmouth. It does spit out but sometimes the scoot just won't start. However if I place a latex glove open the bellmouth and kick her twice she tries to fire. I remove the glove and within 4 kicks she starts. Is this weird, is it just me or has anyone encountered anything similar and sussed it out ? The latex glove thing I discovered by accident......honest !! Help.... anyone regards theoldmodcon (thanks for listening)