Motorcycle Repair: timing chain, locknut, chain tensioner

Question
i have a 1981 cm 400e how do you adjust the tension on the timing chain tensioner

Answer
Jon,

there is usually 1 locknut on the rear
of the cylinders between and below the carbs.
-You let your bike idle (1200 rpm) and loosen
the locknut, the chain tensioner inside the
engine should adjust itself automatically,
then you just lock the nut again.
That is the manual version, I believe
you could loosen the locknut with the
engine off and turn the engine
by hand in a forward direction
and then lock the nut. It might
be safer than having the engine
running. If it sounds worse just
repeat the process again.
Sometimes the chain and tensioners need to
be replaced if they are not doing
the job.