Topic: Fork oil question

[75 super sport]

I just changed the fork oil  on my 75 cb750f.  The forks were soft before I changed the oil, and I thought they might be low on fluid so I changed it. I used atf. I added 150 ml  (5oz) of fluif. They are still pretty soft, any ideas?

[Steve_K]

Two things it could be.  Fork springs weak or you could add some spacers to increase spring pressure.   I have a 73 750K and I needed heavier weight oil.  20 wt fork oil is what I used.
BTW, I have progressive  fork springs in my bike.
Steve

[70CB750]

I remember reading Hondaman post on using heavy oil - like 15w40 - in forks.

[75 super sport]

So I do have the correct amount of oil in there? I added 5oz which is about 150ml, which is what I was told to add. It would be 7oz if doing a rebuild of the forks correct?

[ofreen]

The owner's manual for the '75 750F calls for 5.6 oz or 165 cc (ml) of ATF.  I use 6 oz of PJ1 71/2 wt fork oil in my '75F and check to see levels are the same in both fork legs.

[75 super sport]

How do you check the levels?

[PeWe]

I use the oil level recommended by progressive. No springs in, fork completely collapsed, oil level 140mm from top
http://www.progressivesuspension.com/pdfs/forkSprings/3055.pdf

I use a big syringe with a hose that is 140mm in lenght from bottom of syringe. I fill with oil until level cover the hose with syringe bottom against tube, suck with syringe and oil level will become exactly 140mm

Photo when I changed leaking seals and filled fork before assembly. I have to remove handle bar to take out springs, then collapse lift front with jack or press bike down.

Will do this soon again when I need to replace fork tubes, one is scratched. OEM stuff going on front end