DOHC's blue Z1R Refresh

I've been a member of this forum for over a decade, and I don't think I've posted a single picture of my bikes. So here is my first project thread.  I'll give it a shot.  We'll see what happens.

This is my first Z1R (from 2009).


 


My dad had a ‘78 Z1R, which he let me borrow for my motorcycle license test around 1995. At the time I was between my first and second Kz650. Once I rode that Z1R I really wanted one. Such an unusual looking bike, and it rode really great. But at that time there really was no easy way to find one. To this day I’ve never seen another one in person (one that I don’t own).

It wasn’t until Ebay became popular that I started to see them for sale. I bought this bike on Ebay in 2001. I drove a box truck from Boston to NJ to pick it up. In person it wasn't as nice as I had hoped (digital pictures were low-res in 2001), but it was good enough. I rode it as-is for a couple months. In that time it stranded me twice with electrical gremlins, so I put it away for the winter. I had a Kz650 with the engine out at the time, and I decided I should probably put that back together before I ended up with two basket cases. Then 7 years passed. I did get the Kz650 back together, and gave it to my best friend (who I had bought it from 10+ years earlier).

So in 2008 I rolled the Z1R from my garage to my basement and did a bunch of work. I had the battery box and swingarm and other bits power coated. I replace the swing and steering bearings. I went through the entire brake system. I sorted out the electrical gremlins, which involved completely reworking the self-canceling turn signal system. I replaced a bunch of missing bits, swapped some aging chrome with better parts from ebay, and many other small things.

I bought it in 2001 with 41482 miles. When it rolled out of the basement in 2009, it had 41950. That right there is how you keep a vintage bike in top condition. Forget about it for 8 years.

I don’t ride the Z1R a lot. I’ve add about 4000 miles since I got it. I took it on a nice trip around the coast of Maine in 2010. In 2011 I got a mint 2006 ZR750S, which was cool except it had the worst seat ever put on a bike. Sold that, and found a 1995 GPz1100 mid-project with the head pulled off. Put that back together, rode it for a few years, and sold it in 2019. I also picked up a 2000 ZRX1100 but let that sit for 4 years without touching it. Oh, and along the way I picked up a basket case Z1R, and then my dad gave me his as well. But those are projects for some other thread.

At this point it’s been about 7 years since I last started the Z1R.

Now it’s time dust if off and get it back into good running condition. Of course I’ll need to redo a lot of what I did the first time. And get around to those things I forgot. For example, I’m embarrassed to say that somehow I never did a valve adjustment. I have no idea why not. Seems obvious. But I guess better late than never? I also never replaced the front tire, which based on the date code I think is from 1985!  

And to try to atone for my lack of photos in the past, here are pictures of some of the other bikes I mentioned. 

      

For about 6 years I didn't have a garage that I could work in, which is a big part of why my projects have not gone anywhere.  About 2 years ago I rented some space in a friend’s building and set up a shop.  I built a workbench, got a Harbor Freight lift, and moved most of my bikes over there.  




My first project was to get the Z1R back on the road.  I started into it, pulled the wheels and carbs off, and was making slow progress.

Then the global pandemic got in the way.  With kids home 24/7 it was very inconvenient to leave and go over to the shop.  So Z1R sat for a whole year with no wheels.  

Of course, the only bike remaining in my home garage during that time was the ZRX.  I didn't bring it over to the shop because it was my lowest priority project, but since it was in my yard it turned out to be the easiest to find time for, so I got that running instead.  At the moment the ZRX is my only ridable motorcycle.

But over the past 2 months or so I've been working on the Z1R here and there.  Here is how it sits now.  Seems like negative progress? 


 

I like the Z1R best of all those bikes, but I have trouble nowadays riding any of them.  One thing Kawasaki never learned was how to build a comfortable seat.  My Z1 seats feel like I'm sitting on a piece of 3/4 inch plywood.

wrote:

I like the Z1R best of all those bikes, but I have trouble nowadays riding any of them.  One thing Kawasaki never learned was how to build a comfortable seat.  My Z1 seats feel like I'm sitting on a piece of 3/4 inch plywood.

That Z750S was really something.  So bad!  It had just 1350 miles on it when I sold it, and it was 6 years old and I was the third owner.  I think it never got ridden because the seat sucked so bad.  Really nice otherwise.

I have a Corbin that I found on Ebay on my Z1R.  It's actually really comfortable.  

I have a Corbin on my KLR and it's not bad.  The higher sitting position on a dual sport also helps because my knees aren't as bent as on a Z1.  

Are you going for a full resto on the Z1R?

hardrockminer post=849255Are you going for a full resto on the Z1R?

Nope. I just want it to be in good working order. 

My primary goal was to adjust the valves and go all through the carbs.  It always ran well enough, but it's never been right.  It came with pods and different mains, and the mains never seemed right.  It also has never idled well, and the one time I tried to vacuum sync the carbs it was clear that it wasn't pulling enough vacuum.  

I also figured I'd change both tires and check out the brakes to make sure nothing was stuck or leaking since it's been sitting for so long.  

The first thing I did was pull the carbs and the boots.  The boots definitely are dry and cracked, and the carbon deposits on the face of the intake port sealing surface make it look like it was definitely not making a seal.  





I also broke the carbs completely apart and cleaned everything.  I've cleaned the ports and pieces many times, but this was the first time I went all the way.  The final step was some time in an ultrasonic cleaner with aircraft ("Extreme") Simple Green.  They came out nice.  The only parts I polished were the top caps, with a bit of Mothers and a cloth.





As far as restoration, if I ever go for a full restore it would be with the basket case Z1R.  It's just boxes of parts and a bare frame at the moment.  Seems like a good place to start.  But first I need to get my dad's Z1R running again, and then on to my dad's Z1.  The list is long.

I did talk to a local hot rod/custom shop about painting a spare set of bodywork for this bike.  But that stalled out last march as well.  The only part of this bike that still has the factory paint is the front fender.  The color on the rest doesn't really match and the pinstripes are all gone.  I have the pinstripe kits for it, but I'm not sure how well they will be able to match the paint.  I should go talk to those folks again.

My plan with the carbs is to return to the factory jetting with the original airbox and snorkel.  My hope is that with the factory jetting, the stock airbox, new carbs boots, and new airbox boots, that it might just work like it's supposed to?  Maybe?

I know for certain that I am NOT looking forward to mounting the carbs with that stupid airbox in place.  I hate that thing.  Maybe the fresh rubber bits will make is slightly less frustrating.  But if it makes the bike run well in the end, I'll probably decide it was worth it.  As Kaylinator said, "Reinstalling a carburetor with the stock airbox will make you rethink every life decision you've ever made."  

One issue is that I'm currently running a Dyna-III igniter box along with a DRL-300 rev limiter.  These are mounted on a plate I made above the battery, which is where the snorkel is supposed to go.  I'm not sure where to move those.  I might just switch to the Dyna-S to get rid of the igniter box, and then figure out where to stash the DRL300.

 

The carbs looked really dirty before you cleaned them.  They look good now.  They are pretty rare....VM28SS carbs were only used on the Z1R as far as I know.

You have a lot of projects.  That means a lot of money spent!

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VM28SS carbs were only used on the Z1R as far as I know.

​​​​​​The vm28 without pumps were only used on the '78 Z1R, but 28s with pumps were used on the 79 and 80 models.  

You have a lot of projects.  That means a lot of money spent!

Not yet!!  I've saved a ton of money so far by not having enough time. 

But it is surprising how expensive even the basic maintenance is.  Tires and tubes and seals and gaskets and brake rebuild kits add up pretty fast.

I have also, finally, adjusted the valves.  The intakes were ok, but the exhaust valves were all a bit tight, and one was nearly all the way tight.  I moved shims around and only needed to buy one new one.  

I had never had the cover off in the 20 years I've owned it.  As I said it my first post, I have no idea why I never bothered to check the valves.  I wasn't sure what I'd find, but everything looked clean and tidy.  The cam lobes look fine.  Maybe not prefect at the tip, but fine for 45,000 miles.  I did notice that the chrome plating on the sides of the shim buckets was pretty worn through.  I didn't take a picture.  It's definitely showing the copper layer under the chrome, with the most wear at the center and wear tapering to chrome at the top and bottom.  I not sure if I should do anything about the buckets.  I've only put 4000 miles on it in 20 years.  Do I really need to worry about those now?  Maybe they can wait?

I also replaced the tach-drive housing and all the seals.  There was a fair bit of oil leaking into the tach cable, so that was overdue.  

Here is a question.  I pulled the valve cover gasket off the head when I was monkeying with the shim removal tool.  In the end I just pulled the camshaft out.  The gasket was glued to the end-caps so I cut the sealant with a razor to take off the gasket.  I did not remove the end-caps.  I have a new cover gasket, but does it need to be glued to those end caps?  Can I just pop it on as is, or should I pull the caps and get out the ThreeBond and do it all again.  They had not been leaking in the past.

The gasket is not glued to the end caps.  I normally check the caps to ensure they are flat and then lay the gasket over top.  I use OEM gaskets only.  I will add a bit of grease to the bottom side before laying it down.  This makes it easier to remove when re-opening the valve cover.

I have a B4 with VM28SS pumpers.  Very nice carbs but right now they're not on the bike.  I'm running 1976 VM26SS carbs instead.

When I install shims I will measure them with a micrometer to make sure I know their thickness.