CB 550 Fork Advice

[Seamus]

I was checking a friends CB 550 K4 for MoT time. I noticed that when sitting on the bike and holding the front brake on, it was possible to rock on the forks and get them to dip a long way. The front felt very soft.
First decision is to replace the fork oil, is the standard grade OK or would it be best to go for something a little more viscous?
Other possibility is that the springs are past their best, How would I know without pulling them out?

As usual, advice appreciated
Cheers
Seamus

[Bryanj]

(1) 20 or 30 weight fork oil is good as specific fork oil did not exist when these were built

(2) you cant

[Seamus]

Thanks Bryan

I guessed the second option was a non starter, but you live in hope..

Cheers
Seamus