KZ750 LTD Fork repair options

Hi all,

When I got my KZ750 H2 a couple years ago the forks were leaking, so one of the first things I did was replace the seals and oil. When doing so I noticed that the forks were slightly bent (not visibly so, but against a straight-edge there's definitely a curve), but without any viable replacements I just put them back together to leave for another day. I had a couple of years and ~15,000kms without issue. But now after sitting a while due to corona, they've both started leaking again, and now I want a permanent fix.

New stanchions run to about $600, but since my bike has ~115k on the clock I'm willing to bet the lowers are worn too, so I'm not keen on spending $600 on the uppers and just hoping for the best. I really need new or good 2nd hand forks. So my questions are:

* Are KZ750LTD forks weak and expected to be warped, or is it just mine and due to the high mileage? Are 2nd hand forks a good option?
* Are there any other models that have similar forks that are an easy swap?
* Does anyone have a good set of spare forks that they're willing to ship to Australia? These bikes are much rarer here.

I know there is the option of a front-end conversion, but as appealing as a modern conversion is I just want it ridable soon.

Have you try ebay for the whole fork assembly? I was looking for fork for my 89 ZX7 and had come across more than a few H model forks. No, not my H1 but KZ H models. Of course, the seller is the one claiming to be a H model fork, so I'm not sure if those are indeed H model fork. One other thing may be the shipping. I live in Hawaii, which is still in states, but I almost have to sell my kidney to get big or heavy stuff ( I can't remember how many kidney I had to sell......................), so been there at down under not gonna help. But worth a try?

I have come across more than a few seller who worked out a deal on shipping. (Something like I pay 2/3 or 3/4 and they will pay the rest).

The lowers are probably fine. Check your manual to see if there is a spec, but unless you've seen metal filings when you changed the fork oil they are probably good as new.

You should be able to pick up a new set of uppers from Z1E or another supplier for around $100. Seals will be fairly cheap. Total fix for under $150.

Can you swim?
suspensionsrus.com.au/index.php?route=pr...ath=49&product_id=94

Thanks for all your replies.

I've had a look at ebay for whole fork assemblies. There are none in Australia, and while there are some in the US they don't look particularly inspiring. These ones look like the best bet, but if I go for them then I'll be trying to negotiate on shipping. $300 shipping for a $100 item isn't nice.

If anyone can point me towards uppers for $100 I'd be very grateful - my local store priced them at over $600AUD (~$400USD). Z1E don't have any listed for my mode ('81 KZ750 LTD).

Has anyone had forks straightened before? I've always heard that it wasn't worth it unless it was a rare bike with unobtanium parts? Since the bend is only marginal and there's no buckling and very little risk of damaging the chrome, that might be the difference though. I'll contact that group and ask.

How's about here?

buyee.jp/item/search/query/KZ750/categor...68?translationType=1

Not sure what the shipping will be though.

Tubes can be straightened if the bend isn't very severe. Do you have any idea how bad the bend is in these tubes? If it were me I would try to find a reputable machine shop in your area and ask them if they can handle something like this. Having a machine shop measure the bend in your tubes is at best a 10 minute job if you have the tubes out of the lowers. You can make a "rough guess" on how bad the bend is by putting the tubes on something you know is flat and rotating them slowly while trying to slip a feeler gauge under them at the high point of the bend. This won't be exact but if will give you an idea of how severe the bend is. Using a dial indicator would be better but you may not have one. Remember too that once tubes are bent they lose some of their resistance to being bent again. There is a place in the US called Franks Forks or Forking by Frank and they make fork tubes for a ton of different motorcycles. They have a website and you may want to give them a shot at getting you new tubes. Lastly, if you find a machine shop that can handle straightening the tubes you may want to see if they can measure the top "bearing" surface in the bottom tube for an out of round condition. Running a bent down tube for a while could conceivably wear the bore in the bottom tube oblong which would not be good, but again it depends on how bad the actual bend is. You may also see marks worn into the fork tubes from the sliding motion of the upper and lower tubes working against one another. Think of it as an oval piston trying to run in a round bore or cylinder. Good luck.
Rick H.