Topic: NobleHops restores a 1975 Z1

[NobleHops]

Hey-o,

Forgive me Honda friends - I strayed into Kawasakis! This is a migrated thread - Sorry if it gets a little discontinuous in spots, but I wanted to keep the quoting to a minimum. We're nearly caught up, thread open for business.

[NobleHops]

Here's the bike:



That's a 1975 US-spec Kawasaki Z1 900. I bought in San Jose, California a year or so ago, and drug it here to Arizona when we moved here last summer. We're calling it "The Friendship Bike" because I'm restoring it for fun and then I am shipping it to my friend Pius in Switzerland. I met Pius in 2011 on an Edelweiss tour of South Africa, and we've since toured the Alps and Dolomites together, plus a giant loop of California last year. My hope is to finish this restoration in time to ship it to him before our next adventure this July in Europe.

[NobleHops]

So here's a better overview of the bike and the project.

It's a 75, was lightly molested by some or other of the previous owners. It's missing the stock turnsignals and mirrors, rear chrome fender. Has a Dyna ignition and coils, badly installed, coils are shorting madly when the bike is running due to some really poor wire construction. Has a period Kerker 4>1 that was repainted at some point, it's solid and looks good, but I can't get it into Switzerland with that on it, so there's a Doremi repro exhaust in the attic that will go on when we're done. Wiring seems "ok", there's some weird vampire tap under the tank doing nothing that I can see, and the starter cranks slowly even with a full battery, so that may need rebuild in addition to cleaning and renewing all those connections.

Has pod filters, will be returning to factory airbox and filter. Have not determined what jets are in it, carbs are on the bench though getting a mini-cleaning while I assess the condition of the bike. Fuel lines were cracked and leaking, carbs leaking and plugged, petcock leaking, tank mildly rusty. Missing the centerstand spring. Seat recovered. Single disk front, will be converting to a double.

Plan of attack is to quickly get it running as well as I can without spending a ton of time on it to assess the health and condition of the engine and transmission, see if it needs to come apart. I did a cold compression test yesterday, found the following values:

1 - 125 PSI
2 - 140 PSI
3 - 125 PSI
4 - 125 PSI

Cleaned and replaced the plugs and was able to get the bike running on three cylinders for a few minutes, discovered the bad coil wire, and repeated the compression test - everything but #1 went up about 10 PSI. I removed the carbs and float bowls last night, blasted the jets clear and gave the float needles a quick wipe. cleaned the nasty pod filters and left them to dry overnight. Will set the float heights and reinstall today.





As above, today I am going to recrimp the sparkplug wires and see if I can run it a bit longer, repeat the compression test and see if it's smoking to any great degree, see how noisy the cam chain and head is, how it shifts, etc. Then I'll make the call about going into the engine. It is showing only 6700 miles on it, so unless that's BS, it may not need anything other than a good servicing.

The chassis will get the full teardown for sure:

Rebuild all brake calipers, new pads and parts, brake lines. Converting to dual front disks. Rotors will be sent to my pal Tom at TrueDisk for resurfacing.

Fork will get teardown, replace the seals and wear parts, new springs and some flavor of cartridge emulators, either Racetech or Ricor.

Steering head bearings will be replaced.

Swingarm bushings/bearings will be replaced and I'll put a modern zerk fitting on it while its apart.

Planning a set of Hagons for the rear, sprung to match the front.

Wheel bearings will be replaced.

Wheels will be re-laced, probably with new rims.

Frame and swingarm will be refinished, still mulling paint or powdercoating for that.

Anything steel will get replated, most anything alloy will get vapor blasted, and anything chrome will get replated or replaced.

Seat will be recovered or replaced.

Gauges will be replaced with repros, in KPH.

The bodywork is all going to be replaced with the reproduction stuff that Z1parts.net and other vendors sell. We're returning the bike to a correct factory color scheme for a 75 - blue.

So that's the overview. More later after I see what I learn today.

[NobleHops]

OK, I ultrasonic'ed the jets yesterday and set the float heights to 24mm, put them back on. Going to fire it off the aux fuel bottle shortly and see what I can learn about it. Will report back.

[NobleHops]

Just measured - they are 26s. I will look a bit harder for markings - it would be good to know what they are correct for.

Steve, they have 120 main jets in them now and 17.5 pilots. It's currently got pods and a Kerker 4>1, but I will be putting a stock airbox back on plus a repro stock exhaust. Would you hazard a guess about what a good starting point might be for the main jet? Seems like that pilot jet is a stock size from the little bit of reading I did on that other site, but if you've got thoughts about those too , I'd be very interested.

[NobleHops]

The pilot jets are correct and the main should be 112.5 but the 26's were on the KZ 900 and KZ 1000. Too bad they're not 29's. They were the hot setup for the bike. You can get stock 28's if you want to keep it stock. That will depend on how much has been changed. Z1E has a chart of codes. I'd compare the parts to see if it's a clone or not.

Great info, thanks a bunch.

I am not shooting for a highly original result, it's going to have a bunch of repro parts on it and it has a Dyna ignition already. Going to get Cartridge emulators, better shocks, etc. It might make sense for me to see if I can find a set of 29s before I rebuild these - I'm going to be buying jets and and and.

I'll go look at that carb info in more depth tonight, see what years had what carbs and see what I'm shopping for.[/quote]

[NobleHops]

Yeah, all research says these are KZ900 carbs, and a quick skim of eBay shows that the 29mm smoothbores fetch as much as $500 for a set, Probably not in the cards,



This page had good reference data and identifying info:

http://www.z1enterprises.com/Z1carbguide.aspx

And now I smell like gas...

[NobleHops]

My 28's have duel fuel inlets.
Steve

Great stuff, super helpful, thank you guys very much.

They are definitely 26s, have dual fuel inlets, and the petcock has dual outputs obviously. They are in very good condition, and they have the common throttle shaft that some folks seem to think makes it easier to keep them in sync from what I read. So I'm gonna stick with them, give them a full strip, ultrasonic clean, swap the main jets for a smaller size and make sure the needle and air screws are adjusted correctly.

I got halfway frustrated trying to run it today, stupid stuff. The petcock is leaking, so I intended to run it off the little aux bottle, but I didn't have a tee large enough to fit in that monster fuel line, so that was leaky too. I got the carbs back in and fired it anyway, ran a float bowl worth of gas through it and it ran 10 times better than it had during the year I've had it kicking around. When the dripping gas made it to the header collector I relented and shut if off, ordered every possible tee and adapter I could ever need and as soon as Brown Santa drops those off I'll get to run it longer, run a proper compression test and make the call about what I do or do not do to the engine before I remove it from the frame.

Did sort out the janky coil wires though. When I was fiddling with it yesterday I could easily hear *SNAP* *SNAP**SNAP* from up near the coils, sure enough, giant sparks were flying out from the Dyna coil terminals, and that was when I discovered it was only running on three anyway. I pulled off the coil wires to discover that they had been assembled like so:



Fortunately they had been crimped so poorly I was able to reuse the terminals, stripped them back properly, trimmed them clean and put a little shrink tubing to insulate. I have some boots inbound, but this did the trick for the time being, no more cool spark show and it ran on all 4, Bonus!





Contented myself for the rest of the afternoon chasing an oil leak and replacing the oil line on the H2, cleaning and lubing the tach cable, fitting some side cover grommets, stuff like that.

More tomorrow...

Nils[/quote]

[NobleHops]

...

Looks like there is some oil leakage coming from the O ring around the cam chain area. That means the top end needs to come off. Depending on the mileage you might need a valve job, definitely valve guide seals. Viton ones. They can be had on eBay for $26. While I was in there, I replaced the valves, springs and valve guide seals. My springs were 40 years old and shot. They can test good but in use, can cause noise, flutter and even a nicked valve on a misshift.  / :evil: Best to replace them. $68 eBay.

Super helpful, thanks.

[NobleHops]

OK, I'm gonna stand down on the whole idea of not taking the jugs off, I think Steve's idea was the right one. Those valve guide seals are bound to be old and punky and i'm sure the cylinders would benefit from a rehone at the minimum, and the valves and springs ought to be inspected too.

So I am doing the carbs today - have soda blasted them and stripped them down to little bits, and it's all making trips through the ultrasonic cleaner today.



And then I will start taking the bike apart in earnest, 

[NobleHops]

OK, I owe this thread an update.

Much progress to report. As prior, the carbs are all the way apart and blasted and ultrasonically cleaned, and my rebuild kits arrived a few days ago. Will tackle that shortly, but at the moment I am concentrating on disassembly so I can get some stuff sent out for coating, plating, etc.

I had some good conscripted labor to work with, and so we did most of the primary disassembly early last week - got the engine out and safely on a dolly, good to go.

 



Broke it down a little further, extracted the steering head and swingarm bearings, photo'd the motor mounts and battery box assemblies, and got all the black bits together, and down to a local powdercoater.







Have been evolving my system a bit on this project - laying out the subassemblies as I disassemble them, measuring and noting the fasteners, then into the bins for replating. I'll have a half-day of sorting to do to get them back together at reassembly, but I'm going to save a bloody fortune on fasteners on this project and the nice replaced zinc stuff looks amazing.



We are very nearly all the way apart at this point -  need to get the plating sent out ASAP, I am of course making a list of parts I need as I go, have another big parts order to make. I need to get the rims off the hubs next so I can evaluate them for replating or repainting, and then I'll be ready to start getting the chassis back to a roller and turn my attention to the engine.

There is a big pile of boxes in the foyer as I type this from Z1parts.net and it is taking all my self control to not tear them open and unpack and fondle the new bodywork. I won't last forever though :-).

[NobleHops]

OK, time for a quick update, fits and starts as usual as I wait for suppliers and parts.

All the zinc stuff is back from plating, looks A-. I could have prepared it a little better, pre-polishing or tumbling a few items that had galling on the surface, but it's relatively few items, the rest look awesome and frankly so do they. Don't seem to have a pic but I'll take one, Reconditioned parts look so blingy :-).

All the powdercoat is done, and I will pick it up tomorrow. Unfortunately I neglected to order swingarm bushings, so that's a hold-up to getting that back together, but I did get started on the wheels. There is tool damage on the rims, and I debated repairing it and rechroming, but there are going to be so many repro parts on this bike I decided it was not worth it, so a new set of DID are inbound and so as soon as those arrive I will relace the wheels and install new bearings. So the hubs got cleaned up and the bearings extracted, and that's on tap for this week.







Need one more push early this week, to order a few key parts like those bushings and get a small batch of chrome replated, and then reassembly of the chassis will begin in earnest.

[NobleHops]

More progress. Picked up the powdercoat but they had unfortunately filled the VIN stamp, and I can't take the chance that will cause a problem going into Switzerland, so they are trying to remediate that. We went with 80% glos and it looks fantastic. They are very skilled, I'm sure they'll make it right.

Bundled up a little chrome order, dropped that off, and ordered RaceTech cartiridge emulators and springs for the fork. Also needed swingarm bushings and collars and I'm going to tap that swingarm for a larger zerk while it's apart.




Just for fun in the middle of the project we are doubling the size of the shop and I get to move into the new, but not before I do some work to it. Juggling the two is a fun challenge :-). More later...



I am thinking a set of Hagon shocks would work well. Any advice along those lines?

http://www.davequinnmotorcycles.com/cgi-bin/webc.cgi/HAGON_TWIN_SHOCKS.html

[NobleHops]

Has it been a month? What a month. Sorry for no updates.

I have been furiously setting up the new shop,and there are of course a zillion details related to that.

Raw space:



Cleaning and etching the floor:



Painting it:



Scavenged more lights, cleaned and installed:





Compressor:



Moving in:



Mystery Machine arrives :-)



Big sink:



Air piping:



Blast cabinet:



Setting up 3-phase power:



Office roughed-in:



Shop functional, but not quite finished (are they ever?)



And with that done and a lot of parts in hand, it was finally time to begin reassembly of the bike this week.



...

[NobleHops]

...and so first mystery I could use help with. I installed a set of AllBalls tapered steering head bearings...



...and promptly discovered that the bearing stack is much thicker than stock as usual, and that has the top bridge sitting pretty high on the cap and nut, as shown.



It seems like my options are pretty limited:

- Live with it, although that will in effect raise the fork tubes 10mm for good or ill.

- Machine the notched nut thinner to try and get it on their solidly.

I did not photo this when it came apart, does the top edge of the steering stem indeed sit flush with the top clamp normally?

N.

[NobleHops]

I don't think that's much of a problem. With that tool did you get the races seated all the way? There has to be some adjustment room and that's where it is. I didn't use a tool like that but driving in the races wasn't that easy. You might try heating up the outside of the neck to see if you can get a few more cranks in. After I put mine together, I rode it, then noticed my preload went away. I tightened it down again but it needs another adjustment a year later. It doesn't rock but the steering is a little loose.
Steve

Many thanks

[NobleHops]

Thanks a bunch, much appreciated. The top bearing is a lot taller than the stock ball bearings, that's what I think is causing this. I confess it has me a tad concerned, sitting so low in there.

That's a Park Tools bearing press, designed for this very task. Makes very short work of this, perfect every time. I measured the height of the bearing race before I pressed it in so I could verify that it was all the way home, and it is.

[NobleHops]

Next oddness. Swingarm is assembled but not smooth. I pulled the pivot bolt back out and removed it to investigate.

I had a lot of hardware replated (zinc) including the pivot, but I confess I did not prep the pivot very well before I did, thinking the plater would. Nope. There was corrosion and pitting in the area where the pivot collar rides, and there was also a fair amount of damage on the pivot collar (not the bushing) on the chain side. I purchased a set of the oillite bronze bushings, and new pivot collars, powdercoated the swingarm, put it back together.

So I removed the pivot and took it over to the buffer, and polished it in the area of the pivot collars till it was much smoother. Test fit it again, and its now a lot better in either collar, but not good in both. It turns smoothly and freely when it's inserted just so its riding on one or the other of the collars now, but not both. So clearly, the bushings and collars are not perfectly aligned, but it's not detectable by eye.

I haven't had the problem before, these things went back together fine on my other projects, better to be lucky than good sometimes eh?

So who can give me a good education on the best technique for installing these perfectly the first time in the future?

And following the tutorial, who's got a bright idea on how to remediate this one?

TIA for your wisdom as always.

[NobleHops]

I think I have cracked the code on this issue, and as usual, once I did it seemed obvious, and like I should have sussed it out sooner. It's like when you look for something you misplaced, it's always in the last place you look, right. Funny how that works :-)

ANYWAY


I inserted the pin and watched with a beady eye where it was contacting the collar on the far side. Then the lightbulb went off in my head and I rotated the pivot pin, rechecked. and this became clear, especially when I rolled it on my flat-enough block with a flashlight behind it:



I'm going to see about finding a better pivot pin, that's straight and with less pitting as this one is showing. Anyone have one laying around gathering dust?

Thanks a bunch for your thoughts, much appreciated.

N.

[NobleHops]

Found one on eBay, new, $40 shipped, Done.

[NobleHops]

...

Thinking through how this all clamps to the frame, and what's fixed (the bolt to the frame and the bushings to the swingarm) and what rotates (the collar on the bushing) it's clear that collar to bushing fit is the most important interface. The bolt is not rotating, and neither is the collar: it is clamped by the boss on the frame, all the way through the swingarm via the spacer to the collar on the other side, it's not rotating either when properly installed. It's fixed along with the bolt. The arm is rotating around the outside of the collar.

So while I still think my bent bolt is contributing to the binding, the takeaway is that's not the most important  fit. The collar to the bushing is.  And thinking this through further, that bronze is relatively soft for a reason: it will break in to the new collars as you guys are suggesting. Much clearer in my mind now.

Related question: the dust caps with the o- rings: those are slightly dished so they themselves don't bind, yes?

[NobleHops]

P.S. Agreed, the pitting isn't so much the problem, but the bend is certainly causing friction  (and binding) between the collar and the bushing.

P.P.S. The pitting is relevant because material is missing, and introducing play between the bolt and the collar. Should not matter much if everything was  perfectly clamped and motionless relative to the frame, but with room to move, I think it does.

[NobleHops]

Pardon the delay, I had a big trip in between, my wife's "Bucket List" trip. I am back in the shop now, scratching my head and wondering where I left off in a few respects, and today was Assemble the Carburetors Day.

When disassembling the bike I discovered that I had 26mm carbs, likely off a later KZ900, and so wanting to return it to something close to correct condition, I sniped what looked to be a promising set of 28mm Mikunis on eBay that were advertised to be free, slides moved freely and smoothly, just needed cleaning, etc.

What arrived turned out to be somewhat different than that. The slides were stuck tight, and the float bowls and top caps had been carelessly brightened with a wire wheel, scarring both. I struck a deal with the seller on a 50% refund, and tore them apart.





I sent out 95% of the steel for zinc plating, glass beaded the bowls and covers to remove the worst of teh scars, vapor blasted all the aluminum, and now I am putting them back together.

Will hopefully have a dandy "after" photo for you shortly.

[NobleHops]

Here's your "after shot, but i'm not quite done.



Apologies for the blurry pic, but I need this wee little metal spring. I can't find it in a quick Googling, but I think it might be called a "leaf spring".

[NobleHops]

Stand down on that, For reference, Kawasaki calls it a "lock washer" part #16054-005

Found it on eBay.

Grrrrr