They are drain plugs. Undo them and you drain the wells at the bottom of the crankcase chambers. I use PTFE tape on the threads of mine to stop any oil seepage.
There are no torque settings. The bolts are steel with a coarse Whitworth thread screwing into aluminium, so care is needed not to over tighten, although I’ve not come across a stripped one. For me it’s always done by feel, something you acquire after stripping threads in the past! No doubt someone on the forum will give you better advice.
Hi Tom, Both drain pugs should have a sealing washer. Mine’s fitted with fibre washers and they need to be tightened carefully or the fibre washer will split. But they don’t leak.
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