Good evening, I've recently had a pre-purchase survey which found that the engine stalls in neutral, but starts easily. The owner gets around this by putting it into gear and hitting the disabling button. It will then supposedly work in neutral once warmed up. The engine is a Lister petter diesel around 20 years old. The surveyor said that starting it the way the owner does could damage the gears. The owner claims that this isn't an issue. Should I get a quote for repair and negotiate price down? Any thoughts on possible issues? Supposedly the engine has just been serviced, but oil level is only half full. Would a service normally top up the oil?