1981 GPz1100 B1 Rstomod / ELR "Tribute"

So much cool stuff in this thread, and what a cool bike. 

Well done sir. 

Thank-you!
It's been a whole lot of fun...
Here is an early moning pic. : taken on my way to work yesterday morning, just after Sunrise, 1°C,  the Moon setting in the West 

H.


 

Absolutely gorgeous.

Public holiday here yesterday, so we ride, ride, ride !!!

While returning from an early morning (fresh!) trip to a local areodrome for breakfast,and to watch some aerobatics,
the tacho / voltmeter stopped working

I assumed that the fault lay with the adaptation wiring that I had effected inside the headlight bucket.
(adaptation of '82 GPz 1100 B2 gauges to fit my '81 B1 wiring)
After removing the bikini fairing and openning the headlight bucket, I could perform various voltage and continuity checks...
No issues there !

I then removed the instrument cluster and opened it up, to perform more continuity checks all the way to the actual tacho mechanism.

The tacho / voltmeter needle is actuated by a TINY moving coil, over a semicircular magnet.
After eliminating all else, I reached the conclusion that the movement's coil itself had failed.
That tiny coil's resistance measured infinity ! (open circuit)  

What to do ???

With nothing to loose, after donning my +3.50 reading glasses, I carefully disassembled the mechanism to see if repair was possible.

Here is the movement, with needle and faceplate removed: 



This picture shows the next step in disassembly... 



And here is the movement, un-soldered from the terminal circuit board... 



The coil is so small !
One end of the coils wiring must have  broken / fatigued off its terminal, which connects to the copper spiral return spring.
Murhpy, being ever present, dictated that the wire end that is buried UNDER the windings was the one at fault... 



In order to gain acces to that end of the wire, I had no choice but to unwind that tiny little coil
I unwound just over 9 metres of wire, thinner than my own hair (and that's saying A LOT !)

I then rewound it, very slowly and delicately, ensuring I had left enough wire protruding in order to solder it back to the tiny little spiral spring. 
Before proceeding, I measured the coil's resistance: 77 ohms.



After many attempts to get it re-assembled, with the needle properly lined up and those terribly tiny sprial springs correctly tensioned,
I could connect 12 volts DC to test it....

At 2 am this morning, I proclaimed: " IT WORKS !!! " (much to my surprise, and relief !)

The voltmeter function of the B2 gauges is a blessing in disguise:
There is a button on the front that, when pressed, makes the tacho needle display the battery voltage on a separate scale.
This effevtively enabled me to "callibrate" it to read 12V on the dial, with 12 volts DC applied to the input terminals.



On my way to work this morning I verified that the tacho was indeed indicating the correct RPM, as, in top (5th) gear,
the speedo and tacho needles ran parallel to each other, as they did before. 

Yaay!

H.  

 

Well done!!!!! I wouldn't have tried such a tedious repair. Great looking bike!

Hi again folks...

The Mikuni BS34 carbs that were on the bike when I got it were not in great shape.
Although they worked fine, some external corrosion and pitting made them look tatty,
even after I had re-painted the diaphagm covers and float bowls.
Also, carb #2 seems to have been swopped in from a different set, and "looks" a little different
from the other 3.

I was fortunate to come across a set, in ok shape, for 100 bucks. Bargain!
The add said they were form a KZ1000 CSR.
This is what they looked like in the advertisement on my local FB Marketplace,
with the remanant of a pod filter on carb #3





I de-ganged them and removed all the brass bits, in preparation for deep cleaning...
I had to cut slots in the heads of the screws that hold the carbs on the gang-plate, to use a big flat screwdriver, as they were seized in there pretty good.







My chosen method for deep cleaning is to boil the parts in a STRONG solution of clothes washing powder.
5 cups of powder in 5 quarts of water. In this concentration it is pretty caustic stuff !
10 minutes on the stove, stirring regularly...
(I learned this method years ago, restoring vintage model aircraft engines that had years of varnished caster oil and crud on them)



After thoroughly rinsing in fresh cold water the parts look almost new...
I polished the brass bits in my lathe using a scotch-brite pad.
All orifices (orifi?) were carefully cleared using suitable pieces of guitar string.
The holes in the emulsion tubes and pilot jets are very small, so I used a strand or two of some stripped
copper wire to clear those.
New o-rings on the idle mixture screws, and also the float bowl drain screws.
The fuel inlet "T" and the fuel link tubes were in good shape.
New fuel needle and seats went in as well.

I 3D printed the seals on the choke plunger tips, as well as the outer "dust" seals for the choke plunger shafts, and the pilot jet plugs.
I realise that the original outer dust seals were "belows" type, but I could not print that shape, so I designed
them to "slide" on the outside for the plunger shaft. (I see many other Mikuni carbs that use this type of sliding seal)



Re-ganging 4 carbs is fun,  especially getting the choke shaft and all four choke fork parts in the correct sequence!







I live up at 5500ft so I swopped in the main jets (.125)  from the other carbs.
Fully reassembled, with new M5 and M6 pan-head crews and split washers, they look fabulous:





Next up was to set all four  float levels, using the clear-tube method.



I installed them on the bike... I like the contrast to the black engine and air-box!



Did a 100 mile ride yesterday... all good!

H.

My carb guy taught me that using guitar strings is a bad idea unless you have rounded off the end of the wire. When you cut it a chisel point is created by the cutters. It is much harder than the brass jet and will enlarge the orofice every time you push it through. He has an assortment bin full of "resized" jets from guitar string cleaning. He checks every jet with gauge pins and says he is amazed at how many jets are larger than the stamped size from being "cleaned".

^^^ And my carb guy uses 1 single strand out of a bicycle brake/derailleur cable!   His claim is that the single strand is smaller than the jet size, but the "pig's tail" effect of the strand is beneficial.

To each, their own!    

Hi Howard,

Beautiful work.

Following the advice of Wookie, I came here looking for 3D modelisation of mounting brackets for the gpz 1100/750 front fairing and, after a good hour of reading, I must say that I found much more than that. Congratulations on your work, it is amazing. The attention to detail and the skills you have are impressive! Plus the detailed report with very useful tips!
I will definitely come back to this topic while rebuilding my 750 engine.

I saw that you shared a picture with all your 3D designs and I would be very grateful if you could PM me the ones for the front fairing brackets.

Cheers and congratulation again,



 

Michel3007 wrote:

Hi Howard,

Beautiful work.

Following the advice of Wookie, I came here looking for 3D modelisation of mounting brackets for the gpz 1100/750 front fairing and, after a good hour of reading, I must say that I found much more than that. Congratulations on your work, it is amazing. The attention to detail and the skills you have are impressive! Plus the detailed report with very useful tips!
I will definitely come back to this topic while rebuilding my 750 engine.

I saw that you shared a picture with all your 3D designs and I would be very grateful if you could PM me the ones for the front fairing brackets.

Cheers and congratulation again,




 

PM doesn't work but I can put you in touch via email if both are in agreement

Thanks Michel3007 , I had a whole lot of fun making my "Tribute", and I LOVE riding her every day!  



I replicated the original GPz 1100B2 mounting method, with ALL its parts:
There are quite a few parts to print, so I've made two drawings that show what materials to use:

Here is the lower mount that attaches to the front brake pipe manifold (Kawasaki emblem removed),under the headlight: 


Below is the left hand side, upper mount... Right hand side is a "mirror" of this. 
 



Attached are two ZIP files containing the 3D printer files that you will need.
See pics above, showing which printer materials to use.

Regards.Howard. 
 
  
 

That would be great, thanks Wookie