Author Topic: Maui Z1 1973 (Read 47347 times)

Terry in Australia · « **Reply #50 on:** July 09, 2021, 07:21:12 PM »

Ha ha, yeah mate, to be honest, when I'm 70 I hope I only have 3 bikes to worry about, the CB750A I just bought is bike #28 I think, the KZ750 twin that's coming when my client drops it off will be #29, and who knows what #30 will be? (if the wife doesn't murder me before #30 arrives, I haven't told her about the auto yet...) I think by the time I'm 70 I will have given my sons a Harley Sportster and a Triumph Rocket III each, and maybe a CB750 each, if they want one, and I'll be happy to ride whatever I haven't sold by then.

Having said all that, if a 1972 Z1 fell in my lap I'd jump on it, that bike is definitely not a "UJM", the "Universal Japanese Motorcycle" was coined in the early 1980's when all four Japanese manufacturers were building bland, across the frame DOHC 4 cylinder bikes that looked pretty much the same, with the same specs. Your Z1 is the "Holy Grail of Japanese Superbikes", they are rarer than a sandcast, and a nice clean one (restored or original) is worth around $50K here, no BS. You're a very lucky boy!

MauiK3 · « **Reply #51 on:** July 10, 2021, 08:36:31 AM »

I'm still not grasping how lucky I am, this stuff never happens to me. I'm now at the point of "whatever it takes" to get this bike looking and running great.
Right now I'm waiting for some key parts to finish the carbs so I can try to get it running, in the mean time I'm picking around the rest of it making a bank breaking list of what I'll need. Of course the rubber bits are all cracked so there's that. There are a lot of fasteners that are very corroded too. I'm not finding many "Kawasaki dot" fasteners since the po did some work and did not save them.

RAFster122s · « **Reply #52 on:** July 10, 2021, 10:45:56 AM »

The Dot fasteners… would that be JIS fasteners and he switched it to ISO metric fasteners? Is that OK in 73? Thread pitch on JIS changed to be identical to ISO on some sizes is my understanding after a certain date in late 60s to early 70s. Years ago I saw a Honda bulletin about the change. Smaller sizes of fasteners remained in the original JIS thread pitch.

Alan F. · « **Reply #53 on:** July 10, 2021, 10:57:44 AM »

Some of this lot are from a 73 Z1, but there are 2 other bikes mixed in: https://www.ebay.com/itm/164901356278?hash=item2664e302f6:g:7dAAAOSw7CpgvV2H

Could you post a pic of these dot fasteners? Is it just the cross-head JIS with the dot or is it a Kawa-specific design on hex heads?

754 · « **Reply #54 on:** July 10, 2021, 12:08:47 PM »

Do you have dot caliper front brake.. has a round circle on it . May not be tge early ? One...
Have some 4 bolt brake bolts. Might have dots.

Terry in Australia · « **Reply #55 on:** July 10, 2021, 05:53:36 PM »

Quote from: MauiK3 on July 10, 2021, 08:36:31 AM

I'm still not grasping how lucky I am, this stuff never happens to me. I'm now at the point of "whatever it takes" to get this bike looking and running great.

Good job mate, don't skimp with that bike, it's worth restoring properly, regardless of how expensive, or how long it takes.

69cb750 · « **Reply #56 on:** July 11, 2021, 06:40:04 AM »

Quote

Can you look at the rear fender rubber damper bracket and tell me if it’s plated or painted? Mine is painted silver, I’m thinking it should be plated but I’m not sure.

Rear fender clamp is zinc plated from factory.
https://www.ebay.com/itm/293416889430?fits=Model%3AZ1&hash=item4451026c56:g:H~0AAOSwgFleGDOe

MauiK3 · « **Reply #57 on:** July 11, 2021, 08:11:57 AM »

I removed all the layered on black paint to find a nice coat of zinc. The po was in love with black paint, it's thick and it's everywhere. I'll look at the brake caliper and get a close up photo. I put one on this but I may need to get a closer photo.
I'm going nuts waiting for carb parts.
My kick starter cleaned up nicely except for the washer and e clip that holds it together. What I have is flaky chrome plating on those two parts. Looks bad. I'm wondering if the kick starter is original. If it is I'm going to need to find a better e clip and washer.
Those two parts don't seem to be available separately.
As for date stamps. My frame label says the build date was 10/72. The date stamp on the swing arm is 3 03 which I think means it was built March of 73. This seems odd unless the frame was built and sat around somewhere in the factory until March and then was assembled. Confusing

69cb750 · « **Reply #58 on:** July 11, 2021, 11:27:13 AM »

I have Z1 44 after yours.

Quote

My kick starter cleaned up nicely except for the washer and e clip that holds it together. What I have is flaky chrome plating on those two parts. Looks bad. I'm wondering if the kick starter is original. If it is I'm going to need to find a better e clip and washer.
Those two parts don't seem to be available separately.

92022-085 washer - https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=92022-085&_sacat=0
482J0-100 clip - https://www.mcmaster.com/circlips/side-mount-external-retaining-rings-6/

Quote

As for date stamps. My frame label says the build date was 10/72. The date stamp on the swing arm is 3 03 which I think means it was built March of 73. This seems odd unless the frame was built and sat around somewhere in the factory until March and then was assembled. Confusing

October bikes have 209 and 210 swing arms, your bike was built last two days of October, (mine too), more likely 210 but could be either.

Your caliper is original, disc has been replaced.

MauiK3 · « **Reply #59 on:** July 11, 2021, 02:15:04 PM »

I’ll check those links out.
I attached a close up of the caliper, pretty rough. Since I’m going to dual disc it (since it’s set up for it) I’ll need two stock discs and all the other stuff. The EBC floating disc on it would not match.

MauiK3 · « **Reply #60 on:** July 12, 2021, 08:29:12 AM »

Yesterday I connected my jump box to turn the engine over. Plugs were out.
The good news is it sounded great with no unexpected noises, and the oil light went out quickly.
The bad news is that while it snicked down into first no problem and the back wheel turned, I could not get it to go up into second.
I made several attempts.
Looks like I have some investigating to do there. I would post a little video but I'm not sure how to get my iphone to shrink the size of a video small enough to load on to the site. I need to look into that.

MauiK3 · « **Reply #61 on:** July 12, 2021, 10:47:02 AM »

Compression test
I squirted a little oil in the cylinders and cranked it over.
155
160
150
155
I guess I don't have any big problems with that but the factory spec is 121. Seems as though it's been boosted some. Just looking in the plug holes the pistons don't look domed. The receipt from the 2009 work says he surfaced some of it. I guess that may account for it. I'll need to check things out.

ekpent · « **Reply #62 on:** July 12, 2021, 11:56:46 AM »

Quote from: MauiK3 on July 12, 2021, 08:29:12 AM

Yesterday I connected my jump box to turn the engine over. Plugs were out.
The good news is it sounded great with no unexpected noises, and the oil light went out quickly.
The bad news is that while it snicked down into first no problem and the back wheel turned, I could not get it to go up into second.
I made several attempts.
Looks like I have some investigating to do there. I would post a little video but I'm not sure how to get my iphone to shrink the size of a video small enough to load on to the site. I need to look into that.

Was the counter shaft sprocket or real wheel turning a little when you tried to go to second ?

seanbarney41 · « **Reply #63 on:** July 12, 2021, 12:17:54 PM »

Quote from: MauiK3 on July 12, 2021, 08:29:12 AM

Yesterday I connected my jump box to turn the engine over. Plugs were out.
The good news is it sounded great with no unexpected noises, and the oil light went out quickly.
The bad news is that while it snicked down into first no problem and the back wheel turned, I could not get it to go up into second.
I made several attempts.
Looks like I have some investigating to do there. I would post a little video but I'm not sure how to get my iphone to shrink the size of a video small enough to load on to the site. I need to look into that.

you cannot test Kawasaki transmissions this way. There is a mechanism that prevents shifting into second unless the back wheel is turning a certain minimum speed. Kaaw designed it like this to make finding neutral easy when at a stop.

MauiK3 · « **Reply #64 on:** July 12, 2021, 02:29:27 PM »

Excellent news! The back wheel was barely turning. Good to know.

MauiK3 · « **Reply #65 on:** July 12, 2021, 02:35:51 PM »

Which brings me to another issue. This engine has an oil cooler that is pretty ugly and poorly installed. I always intended to go back to stock. To do this I need to remove the oil line adapters and purchase and install the stock “oil pipe” which is available for about $130 since the PO did not keep it.
This seemed ok until I checked compression which is higher than stock by about 30 psi. This engine likely will run hotter I guess so maybe I need to figure out how to install a better oil cooler.
The other option is maybe try to figure out what changed the compression and revert to a more stock configuration if possible.
Decisions, decisions
This forum is great.

Jeff.Saunders · « **Reply #66 on:** July 12, 2021, 05:07:18 PM »

many owners installed 10.5:1 compression big bore kits in the Z1. Heat is really the issue with that. The extra compression requires higher octane fuel - and does make the engine run hotter.

Providing it was just the sleeves bored out to 70mm (1015cc), then it's not impossible to install new 66mm sleeves and go back to stock. If the engine is bigger than 1015cc, the chances are there are larger sleeves and a bigger overbore.

Stock sleeves technically can go to 71mm (1045cc) - but that makes the wall too damn thin - risking warped sleeves and compression loss.

You can go to 76mm (1197cc) by boring the block and installing bigger sleeves and pistons. This also requires the cases get bored to accommodate the larger diameter sleeves.

The very early Z1 cylinder blocks used a 1-piece head gasket - and didn't have an O-ring around the cam chain tunnel that's found on the later Z1 engines.

Terry in Australia · « **Reply #67 on:** July 13, 2021, 02:29:57 AM »

Yeah, I wouldn't be too upset with an average of 155 psi across all 4 cylinders, although you've done the test with a cold engine that hasn't been run in awhile, so once you get it running it might come up a tad once the rings start to expand back into the bores, but even if it's got a big bore kit in it (which it most likely has, the manual cam chain adjuster is a hint that it's had some work) it's not gonna run that hot that you'll have overheating problems with it, plenty of guys here have hotted up Z1's and aren't even running oil coolers.

Before you make too many assumptions, put fresh oil and a filter into it, get it running and take it for a ride, and when you come back, do another compression test while it's hot and see if it's gone up some more. Don't overthink it.

seanbarney41 · « **Reply #68 on:** July 13, 2021, 02:53:24 AM »

Just for perspective...my kz1000 with big bore at least 10 to 1, Andrews 2x cams(mild street performance grind) NEEDS 93 octane, puts out a lot of heat even with oil cooler, and is a bear to turn over with kicker or starter...never done a compression test.

Terry in Australia · « **Reply #69 on:** July 13, 2021, 03:06:37 AM »

Yeah, but just for a bit more perspective, my CB750 K0 with CB72 pistons runs 170 psi, and yeah it's got some comp when I kick start it, but the starter motor doesn't have a problem (that's why I've installed a CB750 starter motor on my Z1-B with Moriwaki 1100cc high comp big bore kit, Kawasaki starter motors are notoriously weak) and while the hottest day I've ridden the K0 on was in the low 30's (and too bloody hot for enjoyable riding anyway) the K0 didn't overheat, but of course, as with any high compression engine, naturally it loves 98 RON. (probably the equivalent of US 93 Octane) Ride your CB750 on hot days if you have to, and you'll be fine.

ekpent · « **Reply #70 on:** July 13, 2021, 08:10:34 AM »

My buddies 74 Z1A I store for him has had the higher comp 1015 I think big bore kit in it for many many years and has been driven hard and never burned up or had any problems. Sean was down at my shop once when we were going to start the beast but the battery was low. I tried prodding the kickstart with my wrong foot (left foot standing on right side) and the #$%* fired a little and kicked back so hard my foot/ankle was messed up for a half of summer ! OH THE PAIN

As seen in the pic he is a shorter more rotund fella and loves the King/Queen seats to keep him planted under hard acceleration. Somebody out there likes them.

754 · « **Reply #71 on:** July 13, 2021, 08:16:55 AM »

I thought in comprsssion testing you mainly want all cylinders clise to each other.
The number being a guideline , and many reading different than others..

MauiK3 · « **Reply #72 on:** July 13, 2021, 08:25:48 AM »

Yesterday I received two of the three parts I need for a proper cam chain adjuster, I only need the spring now, which is coming. I also got the ignition, fork and seat lock set since the old ones are shot. The fork lock had to be drilled to get it out. I know my cam chain adjuster is not exactly right for a 73 but it will do for now until I can find one. If I find one I expect it will be expensive. I also ordered the "oil pipe" so I can eliminate the oil cooler. We have ethanol free 89 here, I hope it's good enough.
Based on Steve-o's thread about Z-1 carbs I'm going to change my needles since on close inspection with a magnifying glass they appear to be abraded. I also ordered new coils with wires and new ends. I was dry firing plugs and the spark was very weak or not at all. I put my ohm meter on the ends and they measure as open.
I'll get it running eventually, I promise.

MauiK3 · « **Reply #73 on:** July 13, 2021, 07:14:06 PM »

While I’m waiting for carb parts I thought I’d take a crack at the shiny stuff just to see how it cleans up. I did the points cover (which is cracked and pretty beat up) and the little cover over the sprocket, which was pretty weathered. Aluminum takes a beating here if it’s not cared for. I think the aluminum is quite different than what is on my K3, it does not buff up the same, it kind of has a more industrial look, which I like. I took these through 500, 600, 800, 1000, 1500, 2000, 3000, 4000 and finally a buff with brown rouge. Lighting is difficult to get right and some features showed up which I’m not sure I can remove, I may just leave it.
Keeping busy waiting for parts.

MauiK3 · « **Reply #74 on:** July 13, 2021, 07:17:27 PM »

Two more with different light. I’ve got a long way to go with the bright work.

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Author Topic: Maui Z1 1973 (Read 47347 times)