Author Topic: CB400F Forks too stiff, too much oil ?  (Read 7705 times)

0 Members and 1 Guest are viewing this topic.

Offline jacksonc

  • Full Member
  • *
  • Posts: 31
CB400F Forks too stiff, too much oil ?
« on: March 31, 2011, 06:40:39 pm »
I just redid the front forks on my 400 with new honda seals and 150ml each honda ss10 fluid, I know its a sport bike but they don't even seem to budge when going over bumps. An old honda dealer mechanic told me that when they were new people would complain and they just drained out some of the oil because the stock amount was too much, and after they rode a lot smoother. Is it worth a try ?

Offline DarcyCB400F

  • Hot Shot
  • ***
  • Posts: 338
Re: CB400F Forks too stiff, too much oil ?
« Reply #1 on: March 31, 2011, 06:49:22 pm »
I just rebuilt my 400F front forks and used 160cc of fork oil... they work fantastic! Not sure how ml compares to cc... I used a measuring cup from my buddy's wife's kitchen tools. he he

Are you sure you reassembled correctly?

Perhaps you do have too much oil?? Draining some out leaves you not knowing how much you have in the forks... looks like you might have to drain, measure and pour again.
« Last Edit: March 31, 2011, 06:51:24 pm by DarcyCB400F »
1977 CJ360T
1977 CB400F
1980 CB900 Custom
1981 GS550L
1989 DR200R
1998 VT1100C2 ACE
1999 XR400R
2006 CR230F
2007 HD Road King

Offline MoMo

  • Really Old Timer ...
  • *******
  • Posts: 8,275
  • Ride like you're invisible
Re: CB400F Forks too stiff, too much oil ?
« Reply #2 on: March 31, 2011, 06:55:13 pm »
If you are sure all is reassembled correctly, try a lighter weight fork fluid...Larry

Offline jacksonc

  • Full Member
  • *
  • Posts: 31
Re: CB400F Forks too stiff, too much oil ?
« Reply #3 on: April 01, 2011, 07:25:36 pm »
Yes they are assembled correctly, and as I said honda ss10 (10w) fork oil was used in the capacity of 150 ml (5oz) as it stated in the owners manual. 10w afaik is not very heavy oil, there is 5 avaliable but I had 10-30 fork oil in my cb750 nighthawk and its way way cushier ride.

Offline MoMo

  • Really Old Timer ...
  • *******
  • Posts: 8,275
  • Ride like you're invisible
Re: CB400F Forks too stiff, too much oil ?
« Reply #4 on: April 01, 2011, 09:05:36 pm »
I use ATF in my forks, seems to work well.  I weigh 165...Larry

Offline socalenduro

  • Hot Shot
  • ***
  • Posts: 611
Re: CB400F Forks too stiff, too much oil ?
« Reply #5 on: April 01, 2011, 09:19:12 pm »
isnt the oil in the fork more for the rebound stroke than the compression?

Offline camelman

  • Man... Myth... Legend
  • Master
  • *****
  • Posts: 1,899
Re: CB400F Forks too stiff, too much oil ?
« Reply #6 on: April 02, 2011, 09:51:18 am »
I used 15 weight in my 350f and had to let a little out to soften it. It rides great now.
1972 350f rider: sold
1972 350f/466f cafe: for sale
1977 CB400f cafe:sold
1975 CB400f rider: sold
1970 CB750 K0 complete bike: sold
2005 Triumph Sprint ST 1050 rider

We've got to cut it off... and then come down on rockets.  (quoted from: seven minutes of terror)