Repairing, replacing or maintaining a 2003 to 2009 Suzuki SV650's gas tank will require you to drain the tank's contents. Unlike previous SV models, which used a fuel valve and carburettor set-up, the newer generation SV650s use a fuel-injection system that is fed by an electric pump. Although it appears draining the tank would be a difficult process, the fuel pump can be used to your advantage. Setting the tank up for this takes a few minutes, but most of the hard work will be done by the pump itself.
Remove the bolts from under the front of the rider's seat, using a 5mm Allen wrench. Lift the seat up and away from the gas tank until it can be removed completely from the motorcycle.
Unscrew the pair of bolts on the front of the gas tank with a 5mm Allen wrench. Lift the front of the tank up and support it in place with the tank support rod attached to the motorcycle's frame.
Cover the fuel hose on the bottom of the gas tank, near the base of the tank. Pull the hose off the gas tank's outlet pipe. Place a 3-foot length of plastic tubing over the outlet pipe and place the opposite end of the tubing into a 5 gallon gas can. Remove the tank support rod and carefully lower the tank onto the motorcycle's frame.
Unplug the wiring connectors from the motorcycle's ECM (Engine Control Module), positioned just behind the battery and between the rider's seat rails. Place a small length of wire into the connector attached to the yellow and black wire. Touch the wire to the battery's positive terminal, marked by a "+" symbol to activate the fuel pump. The pump will drain the fuel in the gas tank into your gas can.
Hold the wire in place until the tank is completely drained, indicated by the absence of fuel flowing into your gas can. Remove the wire from the battery and the ECM's wiring connector. Plug the connector into the ECM.
Lift the gas tank and pull the plastic tubing off the tank's outlet pipe. Reconnect the fuel hose onto the pipe. Lower the tank onto the frame and screw the tank's mounting bolts into place with a 5mm Allen wrench. Reinstall the seat and tighten its bolts with a 5mm Allen wrench.