Motorcycle Repair: Front fork oil replacement, oil drain plug, honda cb350

Question
I have a 72 honda CB350 twin.  Want to replace front fork oil (ATM oil).  Drain plug is on bottom of front fork.  Having trouble finding where to add oil.  
I loosened up top nut on fork but it won't come free. Feels like it is part of a spring mechanism attached to front fork.  
Thanks for your help.  

Answer
Rob, there is a lock nut under the top fork nut. That is what you are feeling in there. You may have to gently lower the front end down on the ground so the springs get exposed and then either loosen the lock nut from underneat the fork bolt or just use a syringe or small funnel with hose to slip the fork fluid past the edges of the lock nut, if you leave it in place. Oil tends to run down the spring loops and dribble all over the place unless you get the oil down past the first few coils.. go SLOWLY! You may be able to pull the fork bolt upwards to help expose the lock nut, but they are both threaded onto the damping rod inside the fork assy.

The lock nut is holding the spring down in place, so don't back it all the way off....

Depending on what kind of equipment you have in the shop, I have heard of some people using a large syringe to force the fluid back up the drain plug holes... messy I would imagine, but possible.

Bill Silver