Smoking GS

I've realy cleaned my GS behoorlik on saterday ,stripping of all the black covers going in with Clean Green and a tooth brush. Bike looked like a show piece. With the public holiday and all I didn't start it till this morning - it was a bit cool due to the rain last night, anyway - Started the bike just blue smoke out of the exhaust, Does any one know what the problem might be . The bike sounds still OK and pulls like a cracker. Just concerned about the smoke - Should I be ????????