SPARK PLUG size?!?!?!!?!?anyone plZ?!?!!

[AZTIG]

hello people!!! can you guys tell me which the right size for 49cc mini pocket bike it is BM7A or BM6A both NGK ...im comfused which is better!!! when i match it BM6A is longer a bit....

[datalorr]

spark plugs

the number on the plug denotes heat range.NOT ALL PLUG MAKES USE THE SAME SCALE. it mean how quick or slow heat disapates from the cylinder head my FG uses a NGK BPMR7A (hot plug) the same heat rang but made by champion would somthing like a RCJ4,. if i fitted a NGK BPMR4A to my FG the engine would overheat and damage the plug and piston, if i fitted a NGK BPMR9A the plug start to oil up due to the combustion temp being too low, which is better than a melt down, if your unsure use the hotter plug

hope this helps a little