GPZ 750 1984 restoration project

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Re: GPZ 750 1984 restoration project

Postby davidr1963 » Mon Jun 11, 2018 6:35 pm

The_Fixer wrote:Speaking of syncing the carbs, have been thinking about buying one of those Digisync manometers.
http://thedigisync.com/
Not a plug for it, but it does seem to be a reasonably priced option compared to the old vacuum gauge/mercury things, with the claim of being more accurate.

I would wonder what level of accuracy would be necessary, but has anyone heard anyone's opinions/reviews of them? Seems to be a simpler setup and read system with an auto calibrate mode.


I try to get them all within 1cm mercury but it’s a fiddly job and even tightening the lock nut can throw the balance out. That and the levels are constantly changing. It does make a difference though once you’ve got it close.
I like the look of the digital one though and I think I may invest in a set to give it a try. It’s about time I replaced mercury gauges with yellowed tubes!
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Re: GPZ 750 1984 restoration project

Postby The_Fixer » Sun Jun 17, 2018 4:40 pm

Well. I wasn't planning on going this far with the bike at this time, but when I took the swing arm off and found some rusty bushes and dead bearings in the unitrack linkages, time to take the main stand off to get the last bolts out.

That meant taking the engine out. Now it's down to the bare frame. Sigh. I guess we're going all the way now.Removed the wiring harness as well and hit the frame with the Gerni.

The engine is quite light. I could carry the Honda F1 (750) motor, just. This one is heaps lighter. I would say it's a one hand job, but I would be bragging.... ;) ;)

Got access to a sandblaster (industrial), so will repaint the frame, may as well while it's disassembled.
Will tidy up the wiring and re wrap the harness as well. Got heaps of harness tape.
Front forks showing signs of a little internal rust, will have to look into that more. Steering head bearings look like they could be replaced as well. Lots to be done.

Must say I was surprised to see the original rear shock on it still looking great. Boot rubber as well. A couple of minor splits in it, will look at fixing it. Rubber is still quite soft and pliable.

Got some pics, forgotten how to affix them. Will be back later to do so.
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Re: GPZ 750 1984 restoration project

Postby The_Fixer » Sun Jun 17, 2018 5:10 pm

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Re: GPZ 750 1984 restoration project

Postby The_Fixer » Fri Jun 22, 2018 6:47 pm

Just got the fork assembly apart, but the legs are still in one piece.

The manual says the anti dive units need to be replaced every couple of years (service item), so I very much doubt these are readily available nowadays.

Anyone know of a fix or workaround for this?

I am intending to strip the legs and refurbish as necessary, that oil came out pretty black looking....
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Re: GPZ 750 1984 restoration project

Postby davidr1963 » Sat Jun 23, 2018 2:31 am

You often find that the anti dive units have been removed and blanking plates used to blank off the holes.

I read somewhere about how to test them and I’m not sure that I haven’t seen repair kits on eBay but I’ve never heard of them being a service item before.

I’d be inclined to just put them back on and, if you get too much dive under braking, use a heavier weight fork oil. I’m currently using 15 weight as opposed to the standard 10.
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Re: GPZ 750 1984 restoration project

Postby pkay » Mon Jun 25, 2018 12:57 pm

You can check them by dismantling the case and looking at how much movement in the piston. Mine were both frozen but I managed to free them up a fair bit with some penetrating oil and persistence. They occasionally show up on ebay (very rare and expensive). As noted just work around them with oil weight. You can also use the air pre-load as well.
PK
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Re: GPZ 750 1984 restoration project

Postby The_Fixer » Tue Jun 26, 2018 8:42 pm

Okay, thanks guys for your answers.

Here comes another question.....

With the untrack suspension, I have to get new bearings and sleeves (bushings). Any parts around, or do I need to get them made?

If the latter, what steel do I need for the bushing sleeves? I assume your standard bright mild steel wouldn't be up to the job of supporting all those needle bearings. Or are they still available anywhere?
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Re: GPZ 750 1984 restoration project

Postby davidr1963 » Wed Jun 27, 2018 3:42 am

You may still be able to get the bearings; I’d try your local Kawasaki dealer first.
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Re: GPZ 750 1984 restoration project

Postby The_Fixer » Wed Jun 27, 2018 12:36 pm

Yep, Wemoto list the swing arm bearing and seal kit, but nothing for the rest of the linkages.
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Re: GPZ 750 1984 restoration project

Postby davidr1963 » Wed Jun 27, 2018 3:53 pm

I enquired about some main jets at Wemoto which they don’t stock so, on the off chance, I called in at my local Kawasaki dealer. They were able to get them from Kawasaki so I’m hoping that the same will be the case for the shock linkage bearings too as they’re not listed at Wemoto either.

There are a couple of NOS listed on UK eBay too.
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Re: GPZ 750 1984 restoration project

Postby The_Fixer » Wed Jun 27, 2018 7:01 pm

Found these guys in the states:

https://www.megazip.net/zapchasti-dlya- ... -a1-682893

Lots of expensive things, but they seem to have a lot in stock....
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Re: GPZ 750 1984 restoration project

Postby davidr1963 » Wed Jun 27, 2018 7:55 pm

The_Fixer wrote:Found these guys in the states:

https://www.megazip.net/zapchasti-dlya- ... -a1-682893

Lots of expensive things, but they seem to have a lot in stock....
good to know, I’ve bookmarked the site. Thanks
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Re: GPZ 750 1984 restoration project

Postby pkay » Fri Jun 29, 2018 1:03 pm

I've just my GPX750 linkage. The roller bearings are fairly standard and you'll be able to get them from any bearing shop. Also check on the Cradley Kawasaki site parts book and if they list them you can still get them from Kawasaki. The seals are common across the range. The sleeves may be more challenging. There is sleeve that is NLA and hard to find. The others should be easy to source. Do a part number search on eBay and you'll find them. I'm about to do my GPz1000 so be interested how you get on.
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Re: GPZ 750 1984 restoration project

Postby The_Fixer » Sat Jul 07, 2018 9:17 am

Pulled one of my anti-dive valves apart, since it was all but seized. Had to use a 14mm Allen key.
I found an old key which had been cut down, thus lost its hardened tip and drilled an 7mm hole in the middle of the face deep enough to pass over the spigot sticking out of it.

The screw is pretty tight, had to hold it gently in the vice to be able to undo it.

It is in good nick inside, just a little gunked up. Used a blunt scraper and brake cleaning spray to clean it out and it works nice now, light to the touch. The O rings look good, but will try to source new ones from the bearing mobs before final assembly.


My starter motor brushes were worn, but still okay. I ordered a kit from Wemoto. Unfortunately, it is for a 4 brush motor and they don't have anything for the 2 brush type which uses some pretty big brushes, measuring 6 x 14 x 12.5 mm, with twin leads to one connector.
Nobody seems to have anything for it. So I measured them up and went hunting on EBay. Found some in France, about $23 each + $9 post. Ouch. So I got them.

When they arrived, the package showed they fitted a number of bikes, so I went back to Wemoto for another look. They fit several as I said, but the only one Wemoto carries is for the Suzuki 1000 GX (NOT for the GT,GLT or GLX, which have the same part) and they are going for $10.60 each. *sigh*.


So if anyone is looking for these brushes, now you know where to go and what you are looking for. Really need to get to know your parts I guess. But I know now, someone here might be interested as well.

I'm going to my local engineering firm next week to price out getting those suspension bearing sleeves made up. I'll let you know how that goes soon.
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Re: GPZ 750 1984 restoration project

Postby davidr1963 » Sun Jul 08, 2018 4:58 am

I’m not familiar with those models, they’re not UK designations. Do you have a photo of a 1000 GX so I could possibly recognise the UK equivalent?

Cheers
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