Technical Gear changes

[H4UNO]

Hi guys. I’ve just bought this little MK1 uno 45s, and the gear changes feel really scratchy/scrapy. I’ve just had the gear linkage bush changed,as the old one erm… fell out. (Rather embarrassing). But it doesn’t feel any different/better. Could there be something else causing this, and is it likely to happen again?

Thanks guys.