Beta RR 390 2017 Mode D'emploi page 122

3
Measure the spark gap with a thickness
gauge. The gap should be 0.8÷0.9 mm.
If the gap is not as specified, restore the
proper gap by bending the earth elec-
trode.
Check that the insulator is not cracked
and that the electrodes are not corroded,
in which case the spark plug should be
immediately replaced.
Conduct the check by referring to the table
on page 56.
Lubricate the spark plug thread, and then
(when the engine is cold) screw in the spark
plug by hand to its abutting end. Finally
tighten the spark plug with the spanner.
Note:
- Always use NGK LKAR 8A-9 spark plugs.
GB
50