what tool do I need to change the plugs on a 1995 triumph t-bird? I have tried 5/8 and 11/16 and 13/`6 and 13mm and 14mmand 15mm with no success and also what kind of coolant does it take it appears tp be light blue? Thanks for any info anyone can give me. This is not my bike but another guy asked me to get it running after letting it set for several years.