Get the battery off and check the level and top up with distilled water if needed and put it on charge.Only use a charger that has less than 2 amps.It should really be a proper Motorcycle tender type charger.
http://www.ebay.co.uk/itm/OXFORD-OXIMIS ... 416203a9fa
http://www.ebay.com/itm/MotoBatt-Cheap- ... a5&vxp=mtr
Check the state of the oil first.Don't assume it's ok.You can use cheap 10w40/15w40 from the supermarket if you want to do a quick change.You can do the filter later and another oil change.This will clean the stood engine out.
Click here for a read,
http://www.pdsrecording.site90.com/cxgl ... Change.htm
Take the spark plugs out and put some thin oil in the cylinders and spin the engine with the plugs out.This will help lube the Piston rings before they fire up.Don't worry if and when it fires up there's a bit of smoke.
Take the tank off and and the Rad cap off and check the level of coolant in the rad.You can mix your own 50/50 mix with concentrated coolant and preferably distilled water.
click here,
http://www.pdsrecording.site90.com/cxgl500/Coolant.htm
The spark plug needs either a Deep 18mm socket or a proper Plug spanner for 12mm spark plugs.
http://www.ebay.co.uk/itm/New-PLUG-SPAN ... 56529887e4
HTH
