Help with smoke from my 93 Katana

[mmathaifighter]

Ok, last Thursday night I left it out over night where it got pretty cold. Friday I start it up and open up the choke a bit and after about 20 minutes of running it started to smoke a little from under the fairing, looks to be coming from closer to the front upper portion of the engine, also it was idling at around 3000 RPM after i closed the choke. The smoke was bluish in color and seemed to increase when I revved it a little bit. I left the bike alone and today I tried to start it. Started fine with very little help from the choke and idled normally. After letting it sit and idle and revving it up occasionally for about a half hour a little bit of the blue smoke started to appear again. After revving it to about 3500-4000 RPMs for a few seconds it started to smoke a little more. The top of the engine appears to have something thats leaked on it and dont know if this is the cause for the smoke or not. It should be noted that the bike had no issues of smoke that I noticed before the Friday morning startup.

My question is does anyone have an idea of what it could be? Is it worth fixing since it has 26500 miles and I planned on getting a new bike over the winter? Also since I am in Syracuse NY its going to be 55-60 degrees until around Friday and is it OK to ride as is for another few days? Thanks in advance.