new to me '93 Seca II, question

[Sarchi]

I picked up this bike for a thousand bucks, it's in decent shape - has higher mileage (over 50k) so I don't think it was a sitter.  Seller said it hasn't been ridden or started much since July though.  It runs smooth, especially at highway speeds.  But has some fueling issues at idle speeds.

The engine idles high, at least 1500rpm - which the guy claims can be helped by turning the idle screw down once the motor is hot.  He says the bike is known to take a long time to warm up though.  He thinks some carb cleaning/synch is what is needed.  I noticed the bike runs well in gear, but just pulling the clutch in makes the engine rev up to 2-3k.  (kinda disconcerting)

Anyway, I was wondering if this sounds like a big deal.  There's also a bit of a rattle which is supposedly the cam chain that needs adjusting (there's a remote tensioner).  If some carbon has built up I was thinking to try Seafoam before I send the carbs to be rebuilt.  I know, I need to get the bike looked at, check the valves and what not.  But I need a daily rider so I wanted to check if anything here sounds like a major watchout to those who know these older Yamahas.

[FJRmgm]

that high idle on a carb'ed bike is usually indicative of a vacuum leak so check for that.

and carb'ed  bikes of that era were set to run notoriously lean on fuel/air to pass emissions so they were cold-blooded biatches until they warmed up.

[Sarchi]

Thanks for that.  I forgot to mention, it has a Hindle slip-on can (loud!), so I wonder if the carbs were ever re-jetted for it.