Z1R BUILD

[John H]

The template did help. A final test with fuel to double check the petcock uncovered an even worse problem. The fuel level sensor was leaking. I now see why there is a drip tray under it with a drain tube. On disassembly the problem was obvious. The sealant around the rheostat wire had broken down. I carefully removed the old sealant with a small scribe not wanting to damage the rheostat. I then acid etched the area and applied JB weld. Problem solved.

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The petcock had a slow drip so taking a closer look I decided to lap the bore with a fine abrasive paste. Upon reassembly the small spring was missing. A half hour later I gave up and made one. I had to guess at the spring pressure, not knowing its true function. Anyway it's working fine now.
Tomorrow will be startup day. Hope it goes well

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[Lotus54]

That spring will turn up later when you are looking for something else.

[John H]

Yep, the spring showed up after dragging a magnet all over the floor. I'm glad because the petcock was dripping. Problem solved.
The motor wouldn't fire up without a battery booster. The voltage draw due to all the lights is just too much for the battery I have. This calls for a hi-performance battery. Once the motor was warmed up and the oil pressure was good I shut it down to check for leaks. Sure enough the clutch cover showed leak. Tightening didn't help so will remove and replace the gasket.
Next up will be adjusting the carbs and syncing them.

[John H]

With the clutch cover removed I noticed a mis-match of .012" between the upper and lower case halve, only at one place. Now the question is since the upper half has no engine number stamping, were they even a matched pair?

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At this point I will just try to blend the surface with a file and fill the difference with gasket sealer. I super-glued some .003 shim stock to the file to keep the cut just on the upper case. Not perfect, but it solved the leak problem.

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The Hi-performance battery is in and it made a big difference in starting and running. Now, onto tuning.

[John H]

Well it runs, but not that smooth. It won't idle and does the crackle and pop in both the intake and the exhaust. Set the air screws at 1-1/4 but no help. A leak down check was in range with intake and exhaust silent so the crankcase vent sound was clear. Compression was 90#, not unexpected. A short trip down the road and back and compression was 120# on all cylinders and should get better once tuning is finished and a few miles are clocked.

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The spark plug check shows a lot of black suit so first thought is too rich, and second thought was an ignition problems. Another problem could be an air intake leak, none found.
The carbs were removed, disassembled and checked for any possible problem. None was found. Valve clearance was checked and is correct.
Now I'm down to ignition....I think. A quick check of spark plug caps revealed that two of them were between 4 and 5 ohms and two were nil. I'll leave it at that for now. A set of 4 caps are on order.

[John H]

While waiting on the new spark plug caps to arrive I decided to dissect the the old ones. As I recall, the Goldwing caps were such that you could replace the resistors. I was able to pull the end that retains the plug wire out and the resistor dropped out along with the spring. I tested the resistor and it was good but the ends were a bit corroded so I cleaned them, put a drop of copper grease on the ends of the resistor and pressed it back together..It works! I see this cap on Ebay from $70-$90 ea. so they are worth saving.

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Back on the blke and it starts much easier and idles very smooth. But, I still have the popping just off idle and suit on the plugs. Still thinking

[John H]

Took the bike out for a quick blast to see if I could get the rings seated better.
The plugs did look some better so I won't worry about that anymore.

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The motor has had enough heat cycles to retorque the head, and check valve clearance again. Surprised to find 3 at .001" clearance and 2 at .002". I don't think that's tight enough to cause a problem though. It's down to carbs or ignition....which?

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[John H]

Still not pleased with the performance. The occasional spitting/popping is still there at 1/8 throttle and some bogging at full throttle.
Coils have been changed and non resistor spark plug caps have been added. A small improvement.
With the airbox removed now and velocity stacks added the spitting/popping is about the same.
Decided to dismantle the carbs again and recheck everything. Each one got 4 hours in carb cleaner then 10 minutes in a hot ultrasonic bath. Then use air pressure in all openings and passages.

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I'm now reconsidering all the jetting. Us models were jetted different than European models due to emissions standards. Us models ran leaner. I just need to contact someone who has experience with these differences as my jetting seems to be a combination of both models.

[Lotus54]

I sent a message to my buddy with all the Z1s.

[John H]

Thanks for doing that. Today I borrowed a set of VM29's off a friend's 78 Z1R. They have been modified by Yoshimura for racing. Changed the plugs to B7ES and took it for a ride. It ran like a scalded cat and the plug check looks good. As I came back to the shop, it stalled, started up then stalled again.
I'll pull the gas tank and check the strainer on the petcock.
At least now I know there's something about my carbs that are off. I will open up one of the borrowed carbs to see what jetting it has and any other mods that may have been done to them.
Fingers crossed