23 - 91311-PH7-003 O-RING (13.8X2.4) - $1.05
11 - 51430-MCZ-D11 DAMPER, FR. - $134.79
12 - 51432-MS2-003 PIECE, OIL LOCK - $17.38 (same as '03)
14 - 51454-MBW-D61 BOLT, FR. FORK - $17.79
24 - 91356-KA4-711 O-RING (35.2X2.4) - $2.22 (same as '03)
4 - 51404-MR7-003 SEAT, SPRING - $6.14
3 - 51402-MV8-901 COLLAR, SPRING - spacer (could cut your pre 04) - $9.64
5 - 51405-KA4-711 SEAT, SPRING - washer (could use your pre 04.  Same part as '03) - $3.74
2 - 51401-MCZ-D11 SPRING, FR. FORK - $36.63 -  31.43

right fork - $402.82
left fork - $402.82


23 - 91311-PH7-003 O-RING (13.8X2.4) - $1.05		.94
11 - 51430-MCZ-D11 DAMPER, FR. - $134.79	 	126.24
14 - 51454-MBW-D61 BOLT, FR. FORK - $17.79		 15.84
4 - 51404-MR7-003 SEAT, SPRING - $6.14			 5.46


							148.48

add

2 - 51401-MCZ-D11 SPRING, FR. FORK - $36.63 -  31.43

$359.82

write up


Well folks, it took a while, but I hope it will be worth the wait.... I got the parts figured out to convert your pre '04 919 forks into post '04 adjustable forks using OEM parts and such.

[SIZE="4"][B]Stop reading past this point unless you are willing to spend a minimum of $360.[/B][/SIZE] 

The actual cost is closer to $450 to the job right with new bushings, seals, oil & Racetech or Ohlins replacement springs.  It might make more fiscal sense to do the whole job with after market parts from Racetech..  but that's not what this is about.

Also, I should mention that I did not do this.  I bought a set of '04 forks off eBay and replaced the springs, bushings, seals and oil in those.  While I had both sets of forks apart, I did some parts swapping and comparison for you guys.  Also, this is not a "How to".  I am done with writing those.  The part numbers, prices and pictures are for reference only.  It is assumed you either are familiar with the parts and items listed here or you are following a service manual for the actual steps.  I am simply itemizing what you need and showing you what the differences are between the '03/'04 parts.  From this point on I will refer to the forks and parts as 'pre' or 'post'.  That is, for 2002-2003=pre, 2004 to current=post.

I used [URL="http://www.servicehonda.com/parts.php"]Service Honda[/URL] for part price lookup.

[B]Minimum OEM Parts List:[/B]
[COLOR="Red"]91311-PH7-003 O-RING (13.8X2.4)[/COLOR] - $0.94 (uses 2)
[COLOR="Red"]51430-MCZ-D11 DAMPER, FR.[/COLOR] - $126.24 (uses 2)
[COLOR="Red"]51454-MBW-D61 BOLT, FR. FORK[/COLOR] - $15.84 (uses 2)
[COLOR="Red"]51404-MR7-003 SEAT, SPRING[/COLOR] - $5.46 (uses 2)

These are the parts you will need if you are using after market springs which come with spacer material.  If you want to use OEM springs, turns out the pre and post spring is different, as is the spacer.  You can cut the pre spacer to 100mm and reuse it.

[B]Additional OEM parts if desired:[/B]
51401-MCZ-D11 SPRING, FR. FORK - $31.43 (uses 2 unless getting after market kit)
[COLOR="Red"]51490-MCF-000 SEAL SET, FR. FORK[/COLOR] - $ 12.72 (kit contains seal and dust cover, uses 2)
[COLOR="Red"]51414-MAZ-751 BUSH, GUIDE[/COLOR] - $ 3.81 (uses 2)
[COLOR="Red"]51415-MCF-003 BUSH, SLIDER [/COLOR]- $3.85 (uses 2)
[COLOR="Red"]Racetech or Ohlis fork spring kit[/COLOR] - $100 approx (kit contains both springs)

[B]OEM parts you can reuse:[/B]  [SIZE="1"](i.e. free because you already have them)[/SIZE]
51402-MV8-901 COLLAR, SPRING - $8.58  (uses 2)[SIZE="1"](This is the spacer.  You could cut your pre spacer down to exactly 100mm if desired.  This will not be necessary if you are using a Racetech or Ohlins spring kit... you get to cut those spacers to completely different specs.. FUN!)[/SIZE]
51405-KA4-711 SEAT, SPRING - $3.33 (uses 2) [SIZE="1"](This is the washer on top of the spring under the spacer.  It is exactly the same for pre and post, reuse the ones you have)[/SIZE]
51432-MS2-003 PIECE, OIL LOCK - $15.47 (uses 2) [SIZE="1"](never did remove this piece.  Have no idea how it comes off..  just that Honda shows it as a separate piece and both pre and post use same part number.)[/SIZE]
91356-KA4-711 O-RING (35.2X2.4) - $1.97 (Uses 2) [SIZE="1"](take the o-ring off the fork tube cap bolts and put them on the new ones.)[/SIZE]

I have highlighted in [COLOR="Red"]RED[/COLOR] the items I would buy if I were going to do this to my pre forks.  So, add it all up and it comes to a mere  $337.72 in OEM parts.  Add another $100 for after market springs, which you want anyway, and then a little shipping. and handling... and don't forget your favorite fish juice..  say $460 to be safe.  Not bad considering a set of new OEM '04 forks would be north of $760 and that doesn't get you Racetech or Ohlins springs.. that adds another Benjamin.

Now for the pictures.

Obviously, the top valve body is the pre.  The spring below the post valve body is my Racetech 1.0 kg spring.  Incidentally, Racetech specs the same spring kit for all years.
[IMG]http://www.jactup.com/.shag/projects/motorhead/CB900F/pictures/post/valve_top.jpg[/IMG]
[IMG]http://www.jactup.com/.shag/projects/motorhead/CB900F/pictures/post/valve_middle.jpg[/IMG]
The silver thingy (51432-MS2-003 PIECE, OIL LOCK) on the bottom of the valve bodies is the listed as the same part for both pre and post.  Don't be confused by the photos, the valve bodies are completely different.  The top-out springs are set in different places, if I remember correctly?...  This would be a difference in the travel between the pre and post as far as I can tell.  Maybe some one has the information about the travel of the pre?  Honda says 4.3 inches for the '07.. and I assume it's the same back to '04.  Maybe the travel is the same.. the top-out springs look to be in the same posistion in the photos here.. I just can't remember.. sorry :001_unsure: 
[IMG]http://www.jactup.com/.shag/projects/motorhead/CB900F/pictures/post/valve_bottom.jpg[/IMG]

Next pic shows the tubes.  The left tube is the pre.
[IMG]http://www.jactup.com/.shag/projects/motorhead/CB900F/pictures/post/tube_ends.jpg[/IMG]
Honda lists different part numbers for the pre and post for tubes which include the slider bushing already installed..  but when you order the slider bushing (shown on the right) for the post fork tube, you get "This item has be Superseded to a new part number: 51415-MCF-003", which is the part number for the pre fork tube.  I believe this is the only difference between these tubs.  I spent 10 minutes trying to find any difference at all with the slider bushing removed.  Never could see a difference.

From left to right... post, pre & new slider bushings.  
[IMG]http://www.jactup.com/.shag/projects/motorhead/CB900F/pictures/post/slider_bushings.jpg[/IMG]
The superseded part worked fine in the post forks.  Not that it matters if you are working on your pre forks... just making the point that the tubes really do seem to be the same.

Note:  Honda does list the same part number for the lower fork casing.

Finally, here is the post fork guts dropped into the pre fork tube and casing.  Bottom bolt installed and fork cap bolt nearly tightened all the way.
[IMG]http://www.jactup.com/.shag/projects/motorhead/CB900F/pictures/post/fork_guts_installed.jpg[/IMG]
I compressed the tube there on my work bench and confirmed nothing felt wrong.  Seemed to work without issue.

Disclaimer:  I make no claim of competence or knowledge.  I might have completely made all this up in my head?  Use this information at your own risk and for whatever purposes you deem fitting.  As always, your mileage may vary.