car plug can't be installed in motorcycle one should buy proper size proper plug for motorcycle
which is mentioned in manual now its different thing if you buy latest performance plug irridium
but its code or size should match meet your motorcycle
installing car plug can result to disaster inproper plug size Piston can hit plug and destroy itself
irridium plugs for cg125 are available in some shops you should buy that plug if you want buy
better plug for your bike