FORK SWAP?

Hell everybody, i'm new here, this is my first post.

i have an '81 kz650 csr i'm trying to do a mod to, i got a new pair of forks with dual brakes, but the set i've got has bent uppers.

my question is how do i take the forks apart to replace the upper tubes?

any help would be great

thanks,
Dave

Iron Dragon wrote:

Hell everybody, i'm enw her, this is my first post.

i have an '81 kz650 csr i'm trying to do a mod to, i got a new pair of forks with dual brakes, but the set i've got has bent uppers.

my question is how do i take the forks apart to replace the upper tubes?

any help would be great, thanx,

Dave

Hello Dave...save yourself time and trouble and purchase a genuine Kawasaki shop manual (eBay is the source and they are usually reasonably priced)...the manuals are well written, have abundant phots, diagrams, and specs. I predict this is not the first time you'll need a manual either.

Welcome to the madness...

First, are you absolutely certain that you have some straight uppers that are correct? In order to work, they need to be exactly the correct diameter and length. If so, then here is a preliminary list----

1. Factory shop manual.
2. Correct wrenches for all fasteners involved.
3. Factory shop manual.
4. Snap ring pliers for the circlip under the dust boot.
5. Factory shop manual.
6. A strong vice with soft jaws to hold the upper while you yank off the lower tube. A stout friend may be substituted here.
7. Factory shop manual.
8. Air or electric impact wrench for the damper rod screw. Alternately, an allen wrench and special holding tool can be used.
9. Factory shop manual.
10. Solvent to clean out old grunge.
11. Factory shop manual.
12. New seals. As long as they are apart, it is foolish to reuse the old ones, imo.
13. Factory shop manual.
14. New fork oil and a tool to measure the proper level.
15. Factory shop manual.
16. A torque wrench to properly tighten the fasteners.
17. Did I mention a factory Shop manual?
18. Beer.
19. Factory shop manual.

And more beer....:S

What forks are bent? Are they from a 750-Ltd-4?
If so, the bent tubes might be the same as the CSR's.
Assuming they are from the mentioned bike...

Drain the forks & apply some heat to the fork caps w a propane torch, then remove them w a 22mm wrench or crescent wrench.
Dump out the remaining oil. To make the job less messy, pour in some solvent as a rinse, reinstall the cap, invert a few times, then dump it out & proceed.
Apply some heat to the bottom allen bolt, then remove them using an impact wrench w an 8mm allen socket. If you don't have an impact wrench, you'll have to use a tool of some sort to stick down into the upper fork tube to hold the inner cylinder rod while turning the bottom allen bolt.
This might be a good time to go ahead & replace the fork seals.

1981 KZ650-CSR fork parts.
The 750-Ltd-4 forks are very similar.
The head of the inner cylinder damper rod looks just like a 12-pt 19mm socket.

..

sweet, already bought the oem repair manual, hasn't come yet. thanks a lot guys this will help me get started before the book gets here.

Dave

Forks are easy after you figure out how to do them.

Iron Dragon:

Be sure your replacement fork tubes are the same diameter as the present, so they will fit the triple trees OK. The problem with dual discs, is that the two discs are slightly smaller in diameter than the single disc set up. The mounting for each caliper is slightly lower on the fork to accomodate the smaller diameter disc. The caliper mounting will be so low on the disc that it will severly interfere with the disc outside diameter. Yes, there are 4 mounting holes on the right side of your present hub, but the spacing may not be correct. The dual discs bolt to the hub with about 7 bolts versus 4 for the single disc hub. Also the Master Brake Cylinder for dual discs has a larger diameter cylinder to handle more volume, and to reduce the pressure for a given amount of brake handle squuexe. Of course, you will need brake lines for the dual calipers.

Long story short - To make the conversion easy and successful the best way is to have the front wheel and hub from a dual disc set up, plus a different Master Cylinder, and brake lines for the dual system.

So if you have all these parts, then follow the above posts in order to clean and overhaul the "new" forks that you plan to install.

Maybe this may be an over-simplification, but in order to get the forks out of the bike: 1. Place the bike on the center stand. 2. Unbolt the present brake caliper from the fork, pull the caliper assembly off the disc, and support it with a piece of wire so that it does not hang by the hose. 3. Unscrew the speedometer cable from the gear drive beside the hub. 4. Loosen and remove the front axle nut, and pull the axle out of the forks. 5. Move the wheel and hub assembly aside. 6. Now loosen the clamp bolts on the triple tree - 2 bolts on each side. 7. Each fork tube should be able to slide out of the triple tree - some lubrication may help. 8. Reverse the procedure to install. 9. Work with the brake lines for the dual set up, etc. 10. Bleed the brakes, etc.

I have a single disc on my '82 KZ650 CSR, and wanted to convert to dual discs, but did not want to have to purchase all the necessary parts. I am willing to modify things, but there were way too many problems. Good luck.

I've got the front forks/wheel/brakes from a parts bike of the same year & size. I'm just doing a straight swap of the fron forks and all attached parts, but one of the upper fork tubes on the new set is bent and needs to be replaced. I will need to change the discs (didn't know they were smaller, thanks) because someone got the disca ahead of me, and I think i have the master cylinder for the dual setup, but i'm not sure. is the master cyl. different too?