Front fork springs KZ750L4 -1984

Greetings members of kzrider,com!

I got my hands on a kz750 L4 - 1984 a couple of months back, now I'm doing some renovating and rebuilding.
Currently I am looking to buy progressive front fork springs from Wilbers but I can't find specs anywhere for this certain bike, neither could my local dealer. From what I can find on kawasaki.com I only see that the same springs are used in kz700A1 - 1984 (an american version of the same bike with less cc because of some import taxes on bikes over 700cc??). Since I can't find any specs for it I opened up the forks and found springs that were 4,3x25x485mm together with a homemade shim on top of the spring that were 34mm :blink: made out of various washers and bearings, the last part makes me suspicious whether the spring is correct or not.... Do anyone know the original specs for these springs or at least where to find the information?

Thankful for any replies // Henrik Johansson, Sweden.

Manual. 750turbo.com --- Index .
1980-84 KZ750-4 1983-85 ZX750 pdf manual. 750-L4 listed on back cover. good pdf scans.
there is a complete manual, plus sections of the manual divided into 15-20 pdfs but those may be incomplete.

Wiring diagrams. mbsween. bike-night. KZ750L3 . Scroll down & click "The Bible" link.
the site has wiring diagrams & a 750-4 pdf manual that isn't scanned as good as the one on the Turbo site.
Note: some of the wiring diagrams are mislabeled in the links: the 1981 Ltd is an H2, the 82 is an H3, & the 83 is an H4.

Thanks for your quick reply, those documents are very valuable!! Now I have looked through the documents as thoroughly as possible but I can't seem to find the spring lengths for my specific model. I found service lengths for kz 750"H" and "B" but not for "L4" or "A1" Do you know if all different model's springs are supposed to be written in these docucuments, if they are, I need help with my reading

I couldn't find anything specific to the L4 either. You probably already found the table on pg 211 --- the 750-E is probably the closest match. I'm not sure what you should do. I would double check the manual, supplement by supplement. Then use whatever info seems most appropriate. The other L models are probably very similar if not the same.
Then I guess the KZ700 info. then the 750E. ??? ... (I'm assuming the ZX750 forks are different).
Or go ahead & get new aftermarket fork springs & install homemade spacers.

Old springs. yours may not be stock. or they became worn & someone installed spacers to stiffen them. ???
With Progressive brand springs, a homemade spacer is usually required. Since yours measure 485mm & have the washers & stuff in there, they could be Progressives or some other brand.

Yes, found that page too. I just sent an e-mail to wilbers to get their dimensions for kz750E-springs, offcourse they had two different ones hehe Ye, they're probably not original ones, I will wait for Wilbers to return with dimensions and then decide what to do. Appriciate your help and effort Martin! I'll update with which springs that I'll finally purchase!

I recon I'll post an update: So finally I got the answer from Wilbers - they don't know which springs to use fo kz750l4... So I removed the washer made by some of the previous owners and filled it up with the correct amount of oil and air pressure, seems to be just fine now (huge difference from before), however, the bike's not ready for the road just yet so I haven't got the chance to test them during riding!

*Forgot to write that I added a new spacer that brought the preload distance to 20mm. (will measure sag once mounted.)

In looking at Progressive Suspension's website it seems they offer a few different springs for the KZ 750 family of bikes. 1104 for the GPz bikes and 1106 for the E/K bikes. I don't think it matters a whole bunch which you get. The springs come with a chunk of PVC pipe which you have to cut to make spacers so the spring length is relatively unimportant. I've got the 1106 springs in my 750E and the ride is firm but not harsh. And no need to monkey around with air.

Aa ok, agree, probably not too big of a difference between slightly different lengths! With no air, do you run the same oil level and oil weight as original specs? Took a look at your 750E, great looking bike!!!

SWEKZ wrote: Aa ok, agree, probably not too big of a difference between slightly different lengths! With no air, do you run the same oil level and oil weight as original specs? Took a look at your 750E, great looking bike!!!

I didn't even bother looking at the original oil level specs. I simply filled the forks to about 7" from the top with the springs removed and forks compressed. I can't remember what weight fork oil I bought. It was either 10 or 15 weight. It was whatever the manual said to use.

Hehe ok, guess I'll have to take a ride with it once finished before putting any more effort in to this matter

It is well worth sorting that bike out. My 750 R1 handles just so nice, best of the lot. I think the frames are really good, with lots of bracing around the headstock like the later 1000/1100's. .