Torque-wrench needed for replacing sparks?

["The MaZe" <thezeeuw@xxxxxx>]

Hi All!

Recently i have back-fire problems when running on LPG, probably due to a
faulty ignitionsystem. Therefore i planned to change the sparks in the first
place. I did this one a millions time, but now the vendor told me this spark
(Bosch W8DC) needed to be tighten up precize, thus using a torque-wrench! Is
this so? (ig uess it is, 'cause the manuals tells the same...) I allways did
it without. (i don't even have a torque-wrench). So if this all is true, can
someone please tell me how tighten up this one without a wrench? (something
like, tigthen up by hand, and use a tool for a final 1/4 turn or something
like that...)
TIA
Greetinx,
MaZe '86 320i 279 kKm

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