Hello. I recently inherited a 84/85 Honda Magna V30 500 that's in great shape. I had the carbs cleaned before winter and the fuel drained. I started it up this season with the choke open hoping to close it off once the bike warmed up a bit, however when I do the idle drops below 1000 rpm and cuts out. Please help

I don't know the bike but in general if its not been run since the carbs were cleaned and drained I'd follow a fault finding sequence something like:

a Make sure fuel is getting to them. If it starts on choke it probably is.

b check it's not just the idle speed screw that needs a tweek to raise the idle speed. If the carbs have been taken to bits for cleaning and the bike not run afterwards it may not have been reset exactly. Bikes with carbs generally need a bit of help with idle speed until they've warmed up.

c run it on the road for a bit and see if the idle recovers. If not, suspect the slow running jets are blocked. This happens frequently on some of my old stuff if its not used for a while. Try adding some carb cleaner to the fuel and running it, although I've never had much success with that.

d start getting annoyed because from here on in things may need taking to pieces and / or costing money.

e strip the carbs down completely (or have someone do it), check each jet and passageway, float height and needle valve for fuel deposits. It doesn't take much stale fuel, particularly with the idle jets which are tiny, to block them.

I've just got one bike running properly after doing e. and I'm in the middle of doing it with a set of carbs from another. That one had the needles covered in a kind of sticky green gunge that upset the fuel flow to the point where it would run on choke but not at all without it.

Good luck!