@Ronnie hello and welcome Ronnie. If it's been laid up in the garden for a few years my guess is the carb may need a good clean. Take the float bowl off to get to the jets, take them out and blow them through. Maybe just with your mouth and wash with petrol or get a can of carb cleaner or if you're not confident to take the carb apart you could try some fuel system cleaner that you add to the fuel tank but if you get yourself a Haynes manual you can't really go wrong and you'll almost certainly use the manual again and again, definitely a worthwhile investment. As for the powervalve, that may just need a clean to stop it sticking. I'm sure somewhere on this forum there's a link to download the manual for free. Good luck and when you get a chance share a few pics of your new ride.
R
Ronnie
@Ronnie