and since its Saturday, you can actually include a quick look around Chinatown in your itinerary instead of having drinks at Traders Hotel. My suggestion as follows :

1730 Take a taxi from KLCC to Hotel Malaya http://www.hotelmalaya.com.my/index....34CC72DAB0D5A2 which is located in Chinatown. Set off on foot from Hotel Malaya to "Petaling Street" which is where the stalls are located. Have a look around and get back to Hotel Malaya before 7.45pm.

1945 Depart from Hotel Malaya to KLIA with your prearranged airport limo (or a city taxi)

2045-2100 Arrive at KLIA and check-in for your 2230 MH flight to SIN. (You will have one hour at the F section of the Golden Lounge).