Richard's ZR750C1 Restoration Project

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Re: Richard's ZR750C1 Restoration Project

Postby Ivor » 13 Sep 2017, 23:02

just watched the video too , that exhaust sounds great as it is :) loud pipes saves lives
i hate being bipolar its awesome :/
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 13 Sep 2017, 23:34

Very true Ivor but if you're getting headaches it becomes a different story. I did have some correspondence with Delkevic as they advertise with this exhaust as being street legal. Their response was that back at that time in 1992 or so there were no government restrictions on sound level so hence it should be street legal...

I absolutely expect to become pulled over by the dutch police as it still is way too loud. We'll see what happens then ;)
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 14 Sep 2017, 16:52

July 2017

The month July was used to find the bad starting issue having resolved my other performance gap issue by building back OEM only parts within the airtake circuit. I've done several orders this months as during my work I found other parts needed to be replaced. I mainly worked on the valve clearances initially but also took care of clutch (new basket as well...) and sprocket/drive-chain. So what did I order?

work in progress, as will be away to France for a week vacation, to be continued...
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Re: Richard's ZR750C1 Restoration Project

Postby Stu » 18 Sep 2017, 10:41

Without wishing to criticise your work in any way, can I highly recommend to everyone the terminal components on this link?

http://www.vehicle-wiring-products.eu/section.php/205/1/heat-shrink-pre-insulated-terminals

I've found in the past almost all electrical problems I've caused or inherited on old bikes can be traced back to those universal style crimp terminals you've used on the alternator wires. They are not protected in any way, and in the filthy environment under the sprocket cover I'd want something that keeps out the crap and prevents the resistance that has caused the original connector to overheat.

The connectors from VWP form a waterproof seal and in my experience work really well. And they give you a really nice feeling of having done the job properly! 8-)

My crankcase threads were also damaged internally. I built them up with Devcon and retapped the threads. Having just refitted the ignition rotor, I had to file away some of my repair on the inner boss (right in photo) to allow the rotor to clear.
Attachments
Case Fix.jpg
Damaged Case, Mid-repair
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 19 Sep 2017, 23:54

Stu wrote:I've found in the past almost all electrical problems I've caused or inherited on old bikes can be traced back to those universal style crimp terminals you've used on the alternator wires. They are not protected in any way, and in the filthy environment under the sprocket cover I'd want something that keeps out the crap and prevents the resistance that has caused the original connector to overheat.


You're absolutely right Stu, I found this problem to be existing in every bike I owned (all of them over 25 years old). For some of these high current connections I'm tempted to just solder those wires directly to each other. In my opinion it's not the crimp connections that give away, it's actually the connectors themselves that weaken over time making the connection worse increasing their contact-resistance and hence becoming hot weakening them even more and becoming even more bad with in the end a fatal badly burned connection...
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Re: Richard's ZR750C1 Restoration Project

Postby Freddy » 20 Sep 2017, 04:00

For what its worth, I'd use something like this for a 3 wire connector exposed to dirt and weather, rated to 20 AMP. I've got them everywhere in my boat and they haven't failed. Stick some additional silicone round where the wire enters the plugs.

Anything that can stand up to a marine environment has to be good, even normal auto wire won't cut it (lasts about 18 months before being corroded its full length behind the insulation).

http://www.narva.com.au/products/browse/waterproof-connectors-2

I also spray all my electrical connections with a product called Inox MX3 prior to reassembly. Again a product widely used in the marine environment. I don't know if its globally available but some other high performing equivalent would be available. These products are far superior to commonly available de-watering sprays like WD-40 which are just basically glorified kerosene with 'perfume' added.
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Re: Richard's ZR750C1 Restoration Project

Postby Stu » 20 Sep 2017, 13:14

You're right, Freddy... I used those fitting heated grips on my Triumph to match up with the OE connectors. Also available from VWP:

http://www.vehicle-wiring-products.eu/product.php/1237/large-superseal-weatherproof-connectors

Dificult to keep a stock of ones you may need, though!
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 29 Sep 2017, 21:15

Richard wrote:July 2017

The month July was used to find the bad starting issue having resolved my other performance gap issue by building back OEM only parts within the airtake circuit. I've done several orders this months as during my work I found other parts needed to be replaced. I mainly worked on the valve clearances initially but also took care of clutch (new basket as well...) and sprocket/drive-chain. So what did I order?


So let's continue where I left off...

As I mentioned I concentrated on the valve clearances but since I had to drain the engine anyway I also started working on the clutch and many other items while being on it. So I first ordered (only OEM parts as I learned my lesson): tensioner gasket, a set of shims (after I measured the clearance, see below), new oil filter with O-rings, complete clutch housing, plugs for the head cover, head cover gasket, cord grommet (for start motor cable), gear shift lever assembly (mine was corroded), transmission cover gasket, clutch cover gasket. This was the first order but soon I had to place a few more while I was working on the bike finding other parts needing replacement. Anyway this one set me back some 600 Euro's.

Second order at CMS I placed contained: clutch release lever (mine broke while loosening it), rear hub rubber shock dampers, new horn, and all four chrome carburator covers (as mine were deeply rusted). Why you wonder, well if you order enough at CMS you don't have to pay for the shipping. This time it became 370 Euro's

I placed another order at Japparts containing: EBC clutch holder tool, some loctite 243 and liquid gasket for the head cover plugs. Not to bad for 50 Euro's

Third order at CMS: Nut and washer for the clutch, same for the chain sprocket, rear axle (someone used a hammer on mine), rear axle snap rings, left and right rear axle sleaves, rear axle nut and finally the complete housing with switch/cable and all for the throttle handle as the thread was gone on one of the bolts and also because the new one really looks nice ;) . This time I spend 280 Euro's

Fourth and last order: All rear wheel bearings and oil seals, all cables for throttle - starter (choke) - clutch - speedo meter, some rubber parts and bolts for the starter motor and a new brake master cylinder cap. Only for 270 Euro's

To be continued with more details about the repairs I did...
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 08 Oct 2017, 16:39

Continuing July 2017...

As others on the forum advised me to do, I now concentrated on the valve clearances of the engine. Well this was easier said than done, remember I was actually a two stroke guy so camshafts and specifically maintaining the correct timing was something I stayed away from in the past, but not any longer! ;)

So the first step was to free up some space around the top of the engine and remove basically everything above the engine to create some room to maneuver and drain the engine oil which still had the bad smell and light grey color (I replaced it the year before...). I checked the oil with a magnet to see if I could find any iron particles but luckily there where none. I guess the smell and color came from leftovers in the engine from the old oily substance I found during the first oil chance, back then it was really expired oil that came out which was thinned by the fuel that leaked into it thru cilinder #1 (the fuel-lock I experienced during the initial sale). As I removed the oil filter and also removed the clutch cover and let it drip for a couple of weeks during my repairs I hope that most of the previous oil is now gone...

After I removed the rocker cover I found that someone had used plenty of liquid gasket to seal the head, and even with this gooey stuff it only partially succeeded as I found the engine had been sweating oil all around the head. Removing this stuff alone took me several hours, it was basically in every hole you can imagine...

ImageImage

Before taking off the cams I used a marker to mark the position of the timing chain still mounted on the cam sprockets with pistons being at top dead center. The idea was to be sure I didn't mess things up with the timing after I put everything back together. This actually worked initially but since I had to turn over the engine (see below) and I forgot to install the timing chain tensioner it jumped a few teeth and after that I couldn't get the markings back to that position anymore...

Next was measuring the actual valve clearances. I owned a couple of feeler gauges but all of them had a 0,05mm resolution and as I found out later these were not accurate enough as one needs a better resolution so I ordered another one to take better measurements when I installed the new shims. Anyway I measured and took notes of them on the whiteboard as follows where you can see I had to write down the upper and lower size (between value) when using the 0.05 resolution feeler gauge:

Image

From the measurements taken I could tell that the inlet valve clearances were within specs but all the exhaust ones where too tight. Could this be the reason the engine wasn't starting on all cilinders I wondered? Cilinder 4 was basically in spec and this was also the first cilinder to start. Anyway based on this knowledge I ordered eight shims, four with sizes close to my calculations and the other four were one size smaller just in case. I think either Freddy or Stu gave me this advice just before this forum had its crash (boy did I miss this forum while working on my bike!) :cry:

As the new order went in during summer vacation time it took some two weeks to arrive so I next concentrated on the drive chain, the clutch and the rear wheel bearings. Removing the front sprocket became a real burden, no matter what I did. I tried extending my wrench with a one meter long iron pipe but it didn't give up, I also heated the nut with a torch and gave it a good bang with hammer and chisel but still no go. At the end I used a flex to cut 6 sleeves parallel to the nut sides and only then it let go. Reason for me to use the flex as a final step is that I highly respect this terrifying piece of machinery, have seen pictures where things went terribly wrong I mean. Using a flex to me means a working highly concentrated with both hands on the machine ALWAYS!

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As I did found some play in the gear change lever earlier I opened up the panel behind the front socket and found the corrosion on it, nothing really spectacular but since it was now all in reach I replaced that one and all seals as well. I also spend days in getting rid of all the accumulated grease in this area, guess the bike is weighing at least 1kg less by now :)

Still waiting on my shims and while replacing the rear wheel sprocket I found it's bearings to be gone. So I replaced all of them including all seals. During this work I noticed someone had been using a hammer on the rear axle, for what ever reason I don't know and since there were also signs of rust I replaced the rear axle together with basically everything that it touches like snap rings, axle sleeves, nut and washer. So after installing all of it with a decent amount of grease it is now brand new and shouldn't give any head ages for a while ;)

Obviously as the rear wheel came out I gave it a good cleaning job and removed most of the white colored aluminium oxide stains using my sand blaster (loaded with glass beads) so it looks a lot better. Still not perfect but I'm planning to coat the wheels later so for now it's good enough.
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While working on the rear I tried to clean up the rear shocks as well but they were gone and I started thinking of replacing them, also because I suspected them to be unequal while driving the bike. Did some research on The Net as the forum still was down back then and after a while I decided to order a couple of Ohlins at their Dutch dealer hksuspension. They don't come cheap for 870 Euro's but boy-o-boy do they look nice! I had to wait for my sales bonus so I ordered and mounted them few weeks later in August.

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Last edited by Richard on 12 Oct 2017, 20:00, edited 2 times in total.
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 09 Oct 2017, 20:38

Continuing July 2017

Still waiting for the shim order to arrive and having finished the left side of the engine I turned to the right side and started working on the clutch which was slipping under acceleration in high gears. The idea was to replace the clutch plates and install heavier springs at the same time. But I also rembered the story from Stu (was it?) on this forum about the clutch basket having shrunk-and-hardened rubbers so I checked this at the same time.

First thing that happened was I that broke the clutch release lever while trying to remove it (while losening the bolt), no force was used so I guess it was bound to occur anyway and better to have this happening in the garage I would say ;) Obviously I had to order a new one causing more delay...

I removed the clutch cover, the clutch operating plate and carefully removed the clutch plates while keeping them in the same order. I read somewhere the first and last plate could be having a different thickness, in my case they were the same. As I have a C1 I guess it's a modification done later? I measured the clutch springs and they were within spec, actually they did have the same length as the new stronger ones from EBC.

Next I checked for any play on the clutch basket and surely I had the issue as well. I didn't go for the option replacing the rubbers only and ordered a new OEM clutch basket or clutch housing as it is called. I made a recording of the play the old one had so you can check yours when needed



This is a picture of the old and new one. New one on the left has the 3 pins rightfully centered in the sleeve holes:
Image

So next was removing the clutch holding nut, this nut should be used only once. It took a fair bit of force using an extender pipe on my wrench. I even wondered if the thread was counter clockwise but no it wasn't and at the end it finally did come loose. I was glad I ordered the EBC clutch basket holding tool, without it I couldn't have done this. I also measured the thickness of the old plates but they were all within spec, since I had the new EBC set I replaced them anyway. Next I reassembled the clutch again using the new parts including the new nut and in the reverse order. Just to be aware when installing new friction plates they have to be oiled well before installing and so I did.

It will come up later I guess but I can tell you that the clutch is still slipping, maybe a bit less but still very noticeable. Later models, I seem to remember from the model D1 and onwards are using 2 thicker clutch friction plates. I guess I have to order those as well at a later date...

To be continued
Last edited by Richard on 22 Jan 2018, 21:05, edited 2 times in total.
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