Motorcycle Repair: Cam chain noise??, 1985 honda nighthawk, cam gears

Question
Hi Wayne.  I have just purchased a 1985 Honda Nighthawk CB 650 SC. It has about 42,000 km's on it.  I just started to hear a noise today that I believe is the cam chain.  It happens throughout the RPM range, but more so around 3000 to 4000 RPM. It occasionally stops, but it doesn't seem to matter what temp. the motor is.  Because the cam chain tensioner is "automatic" does this mean there is no manual adjustment?  I couldn't find anything in the Clymers manual regarding manual adjustment of the cam chain tensioner. Do you think it is time for a new tensioner?   If there is an adjustment, how is this made?  Also, if there is no adjustment, do you just replace the spring, or the whole tensioner?  Your help is greatly appreciated.  Thanks, and have a good day.

Matt

Answer
Matt,

the camchain is automatic from about 1983 on.
The early 650's had a lock nut at the
rear of the cylinder to loosen and retighten
which set the tension.
Most of these motors make some
noise but the tensioner may need replacing.
The tensioner guides get worn, there
is one on the spring unit and another on
the backside of the camchain.
If you pull the top engine cover you
may be able to inspect it. Turn the engine
forward and back and see how far
the crankshaft turns before the cam gears
start to turn, that may indicate the amount
of slack in the camchain and if the
tensioner is loose/worn.