The '83 GPz 550 (ZX550) Fork Thread

[slygrog]

Hello again,

I've done a bunch of reading and am gearing up to start work on my first bike. Thought I'd create this thread as I've done a bunch of searching on the Internet over the last three weeks and have found lots of people asking the same sorts of questions. Hopefully they will be directed here in the future, to some answers.

First fix that's on my list for the GPz is fork seals. I am replacing a leaking RH fork seal (and a working LH fork seal) with some from Pyramid Parts. The fork oil seals came with new dust seals so I guess they'll go in too.

It seems like you can get away with mostly standard tools for this job. I'm still trying to figure out if I can use a PVC pipe for the fork seal driver or if I should just eat the waiting time and order something like this.

Also, does anyone know if this air method would work for my bike.

Last thing, I think I'd like to install some fork boots/gaiters. Other than, I suppose, girth of the fork, is there any information I need to have about a fork before I purchase the boots?

[slygrog]

ALSO: The shop manual says to use SAE5W-20 oil in the forks. Internet searches are suggesting to me that this is a grade of motor oil and not fork oil?

Is that the case? What does this translate to in specific fork oils?

[klx678]

Well, it's too late for one of my comments. I'd have done OEM seals. For whatever reason it seems the OEMs always work, sometimes aftermarket don't. I worked at a bike shop in sales, but being a gear head I spent a lot of time around the service area when I could. I know the service department eventually refused to do any non-OEM seals due to failure rate of aftermarket. So I only do OEM.

As for the fluid, spend the money and get specific fork fluid. Probably 15w would be good to start, but I'd do some digging to see what the general experience of GPz riders has been. I know from a Cycle magazine article in 1991 that 10w was best for my Zephyr since the kind of riding and the weight of the rider was similar to me. I'm thinking if you find a good GPz or GPz550 forum or thread you might find a good answer. It depends on your riding style and weight. If you're about 180 and a bit sport oriented in riding style you could start with 15w, go lighter if you are less agressive in riding or if you're under say 160 and heavier if you're really aggressive (track days) or weigh over say 220. It's all dependent on the feel... thus my comment to look for a thread or forum for the 550.

[peglados]

Klx678 has good info for you. For sure your best bet is OEM seals. Try DillonBrothers.com. They have really nice guys answering the phones and surprisingly a good amount of parts for your bike. You want to use the best parts available since the seal replacement is interesting but not something you want to be doing all that often. I really reccommend that you get a Kawasaki factory manual. It's got a bike with a tank like yours on the front of it, but make sure it has the '83 addendum in it.Don't bother with the supplement. There's a guy on eBay from England named Stuart that has sold me three manuals for my Gpz's (one for every room!) and they're really in good shape. If you want I will look up his info in my saved sellers list. I use 15w fork oil. While you've got the forks off consider replacing the springs. I use progressive springs. Replace(?) clean and lube the o-ring that seals the air in the forks but I've never actually known the forks to hold air for long and the bike handles well without it. The manual will specify the proper order for torquing the mounting bolts for the forks and brakes, etc. and that will insure a nice straight front end. If you can afford it buy a Snap-On torque wrench. I think they are more accurate and also quite classy! Be patient with yourself and don't do anything that might damage the fork tubes...and enjoy becoming your most trusted bike mechanic! Peggy

[slygrog]

Awesome. I've been buying tools for this and should get to it this weekend. Stupid jobs have been getting in the way.

I was looking at progressive springs online last night, peg. I didn't know what to look for, how to judge their fit/value etc.

Also, is there anything special to know about brake pads before you buy them?

[peglados]

I like the EBC brand of brake pads. I like them because they work but not so well that I have to worry about flipping the bike if I grab them too hard. I flipped a bike at the track that had frodo pads and never want to break another arm that foolishly. If EBC makes a bunch of different pads for "our" bikes I would just tell the sales person my preferences and buy what they reccommend. Same goes for the fork springs. If the springs you buy are specifically for your bike they will come with whatever spacers and whatnot required. The springs I have now have no spacers but the pair I replaced had fairly tall pvc spacers. Just having springs that work will be good. Over time you may form an opinion about what you want or prefer.
The rule of thumb for when to replace brake pads is when they are 50% worn down. When half the material is gone the heat coefficient will cause the second half of the material to wear off quite rapidly. Obviously you may not know how fat the pads were that came on the bike so replacement might be a good way to get acquainted with the whole process...and may help keep the wear on the rotors to a minimum.
I know you are going to have a great time getting to know your beautiful bike and working on it will build confidence in yourself and the machine! Peggy peglados@yahoo.com