My 1981 maxim 650 idles high. what is the correct idle setting and how do i adjust

You need to have the choke adjusted so it runs on a fast idle so the engine can warm up or you may need the carb to be rebuild and adjusted properly.

yes

This could be any one of a number of things. First, it could be a cable routing problem. Double check the routing and free play in the cable. Don't forget to check the free play with the handlebars turned to the locks both left and right. If you loose free play when turning the bars to the stops, add free play to the cable. Second, it could be an idle speed adjustment issue. Try turning the idle down. See if the engine speed responds to turning the idle down.
The next thing to check is proper assembly of the carbs. Double check your work and make sure they are assembled correctly.
The next thing to check would b the intake boots for air leaks. You can do this by starting the bike and letting it run, then spary contact cleaner at the rubber intake boots.If the engine speed alters either way, they are leaking and you can decide if you want to replace them or not. If you intend to keep the bike, you need to replace them.

my 82 seca which should have the same carb set up as your Maxim has a thumbscrew about in the middle of the carbs. i take off the left side cover and can reach in and turn the thumbscrew. then watch the tach as you do . Mine is set at 1050 as per my factory spec. hope that helps

Sounds like you need the carbs cleaned and synchronized, then the idle set once the bike warms up. May also have a cracked intake boot, or a vacuum line off.

You need to replace your floats in carbs, problem solved

hello
if you were to look upward under the carbs, about center between the middle two carbs you should notice a screw with a larger head on it. this is the idle adjusting screw. hope this helps.

when cold it will idle a tad higher 850 - 900 is normal cold , and around 600 warm. if it is idleing high after warm up then check for excessive coke<carbon> build up in intake and throttle valve.