Sign up at myyamaha.com and download the service data sheet for your bike which lists the spark plug type and gap. https://www.yamaha-motor.com/sport/myyamaha/login/L3Nwb3J0L215eWFtYWhhL2hvbWUuYXNweA==/starthere.aspx
NGK plug BP4HS - Gap for PW 50 is 0.6mm.
The spark plug gap for all years/models of Yamaha PW80 and BW80 is 0.024" and NGK part number is BP6HS. NGK plugs come "pregapped" but it's always a good idea to double check before you install any plug, old or new.
The correct spark plug gap is 40 thousands on a stock harley plug
The OEM spark plug is Denso K16R-U
The best spark plug for a stock civic si is ngk.
43/16
Champion stock # 71
The stock spark plug is the NGK DPR8Z gapped at 24 to 28.
Stock Spark Plug gap for the 2.2 Ecotec (no Boost) is .045 inch
.044 for stock h22
.060
Just found this list online hope it helps, it came from NGK spark plugs Spark Plug Part No. Stock No. Plug Gap Photo Iridium CR8EIX 4218 0.028