BR6ES NGK SPARK PLUG Copper
 
M14x1,25, wrench width 20,8mm
Interference suppressed/long thread
Similar to BOSCH WR7CC
Similar to DENSO W20ESR-U
Similar to Champion RN4C / RN5C
 
Thread type:
M14x1,25
Length spark plug thread:
19 mm
Thread spark plug:
Long
Wrench size:
21 mm
Electrode material:
Nickel
Electrode type:
Standard
Spark plug with terminal (grommet):
 
Protective cap is screwable:
 
Heat rating Bosch:
WR6CC
Heat rating Denso:
W20ESRU
Heat rating Champion:
RN5C
 
B6ES - long reach / town and city use / for a standard engine.
 
B7ES - long reach / town and city use / for a standard engine 

B8ES - long reach / local and distance use / for a standard or midly tuned engine. 

B9ES - long reach / competition or distance travelling use / for a tuned engine. 

B10ES - long reach / competition or full race use / for a high tuned engine / sidecar use. 

Spark plugs with a 'BR' denomination have a built-in resistance and are designed for use with delicate electronic equipment (such as SIP rev counter / speedo units). 

Spark plugs with a 'HS' denomination are SHORT reach versions (usually utilised for early pre-S1 Lambretta models manufactured between 1947-'57).

Lambretta models that use a SHORT REACH spark plug are: A + B + C / LC + D / LD + E /F + Lambrettino 48.

Lambretta models that use a LONG REACH spark plug are: S1 + S2 + S3 + GP / DL + J (all versions) + Lui Vega Cometa + Serveta.
 
NGK copper core spark plugs deliver increased heat dissipation for more reliable starts and reduced risk of overheating.
 
Colder spark plugs are suitable for racing cylinders and use over long distances. In this context, the sound thermal output of heat to the cylinder head takes place, there is a risk of sooting, however.
 
Hotter spark plugs are used in sport and standard cylinders. The reach their operating temperature quickly but can also overheat.
Most spark plugs for scooters have a M14x1.25 SW 20.8 thread and are either long thread (19mm) or short thread (12.7mm). Please note: putting a long thread spark plug in a short thread cylinder head will damage the piston.