I'm hoping to pick the brains of the collective experience of the group!
I've just started using my Royal Enfield WD/CO/B after a very long rebuild. I'm having a few teething issues, as you might expect with an old bike, recommissioned by an inexperienced hobbyist. My recent issue is that after a run of a couple of miles on Thursday I could hear a squeak coming from the engine when I got back and kicked it over on the kick start. It sounds like it's coming from the exhaust valve area and is timed with the opening of a valve. I wonder if it might be the exhaust valve and valve guide? As I've replaced both during the rebuild. I did hone it out after pressing it in, but I had a similar issue on the last WD/CO I built where the exhaust valve seized open for a while until the engine cooled down and then it freed itself again. It has the sound of a metal on metal squeak like you get from a slightly rusty and dry nut and bolt.
Could it be an issue with inadequate oil supply to the rockers and valves? I've checked the return into the oil tank and it appears a higher rate than I would have expected as it squirts out of the one way valve rather than drips. Any advice greatly appreciated, I'm hoping I don't have to take the head off again?