Fork oil change, tough to do?

Is this something that I should tackle on my own?

Difficulty 1easy to 10 hard, how is this project?

What is the most dificult part to deal with?

Are there surprises?

Are 'progressive' springs recommended or expensive or even needed?

Hardest part will be removing the drain screws and top caps/bolts.

Maybe a 2 on a difficulty level.

Yes. you can do it.

Do you have a manual showing the procedure?
Have the bike on the center stand, and front wheel off the ground when measuring the fluid level.

Changing the fork fluid is pretty easy, just remove the small screw on the bottom of the fork and sit on the bike with the brakes applied and compress the fork a few times. Now, be prepared for a major shot of fluid coming out the hole, it WILL shoot 5-10 feet away! Replace screw then you have to remove your handle bar and unscrew the cap (under the rubber plug) on top to add fluid. Careful when you do as it will be under a little tension from the spring. If your fluid is very dirty you can change it twice to flush things out. On a scale of 1-10 I would rate it a 3 or maybe a 10 when you shoot fluid all over your garage! :woohoo:

It's easy to do! Do you have the Kawasaki manual; that will simplify things. You must to do one side at a time, or the front end will drop down.

1. Remove the drain screw near bottom of fork leg. (Have a catch pan ready.)
2. Pump down on the handlebars a few times to pump out any remaining old oil (it may shoot out like a squirt gun, so don't do this over an expensive Persian rug.)
3. Loosen the upper triple tree clamp bolt on that fork leg.
4. Remove the rubber cap on top and the fork leg top bolt. When removing the top bolt remember that the fork spring is pushing up on it so it may pop out when you reach the last thread. It simplifies thing if you put a little bottle jack under the engine before removing the top bolt as this prevent the weight of the bike from applying much pressure on the spring. You’ll need to put a jack under the engine anyway to check the fluid level.
4. Replace the drain screw.
5. Now's a good time to pull the spring and measure it. For the '77KZ650C1 it's free length should be 494.5 - 485mm. Replace if it's too short.
6. Put the spring (or a new one) back in the fork tube.
7. Add approximately 165cc of 15W Fork Oil (other folks will tell you to add anything from Vodka to transmission fluid, don't do it! Use Fork Oil - all bike shops carry it.) I highly recommend Bel Ray 15W Fork Oil for the KZ650C1.
8. Temporarily replace the top bolt and remove the bottle jack. Pump the forks a few times to expel any air from the fork internals.
9. Jack the front end up off the ground again.
10. To get the exact correct amount of fork oil in the tube, remove the top bolt and use a rod to measure from the top of the fork tube to the oil level with the spring in and THE FRONT END OFF THE GROUND (remember the bottle jack under the engine). The correct distance for the KZ650C1 is 396mm.
11. Replace the top bolt and rubber cap and tighten the triple tree upper clamp bolt.
12. Do the other fork leg the same way.

Bluemeanie,
I used to remove the handlebars too, but since I change the fork oil every 2 years (for 31 years now - EEEK) I found that to be the most difficut part of the job to do alone. So I came up with a cheap tool to solve the problem. I found a really cheap sparkplug socket that had an external hex that fit into the fork leg top bolt. I cut the hex end off the socket and I can use it on the end of an 3/8" extention to remove the plug without removing the handlebars. Here are some pics:

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I'm sure my caps just have a square hole in them, that a 1/2 drive ratchet fits into.

A quick caveat --

If similar to the large fours, the fork caps are aluminum with very fine threads which screw into top end of the steel fork tubes, usually while firmly pressing down against the spring tension. So it is difficult to determine when the threads are initially aligned and not cross-threaded. Be very cautious here and proceed slowly, as it is extremely easy when starting the cap into the tube to get cross-threaded and strip the fine threads in the soft aluminum cap.

Good Luck!

Interesting 650ed, I'll have to go out and look at my bike. Never really thought that you could get to caps without removing bars. rstnick, yes, we have the 1/2 inch. But we just don't need no stinkin adapter!:woohoo:

rstnick wrote:

I'm sure my caps just have a square hole in them, that a 1/2 drive ratchet fits into.

mine do too

I can get the caps out without removing the handlebars.

BTW: some of the later model bikes did away with those two drain screws.... apparently Kawasaki was drumming up business for their dealer's service bays because the forks had to be removed and disassembled to change the oil.