My XJ750 build, Direction TBD

I figured now would be a good time to get a build thread going to chronological my progress. My intro here: my intro

We learned that I got a pile of a bike that needed, lets say “alittle work”. Well as I started to tear into the bike for the much needed maintenance things took a huge left turn. I merely stated to my wife “hun the one that’s on the bike is ‘broken’ and needs to be replaced” and the parts started rolling in. Parts that need “custom fitting” to be effective. I don’t know the final direction but I have a vision in my mind and see how stuff for the xj/older bikes is so damn cheap why not.

To date here is the list of stuff scored off fleabay and other sources:

Derale Oil Cooler




Cb750 headlight




Xv920 front forks (same as xj but no antidive)



Xs650 dual round gauges



Xv700 Rear spoked wheel
Drag bars (need a 2 inch riser)
Heat grips ! (Xmas gift, See the wife cares about the cold Mornings)
Shims, Thanks Hogfiddles
Carb parts, Thanks Chacal
New throttle and clutch cables
Caliper rebuild kits Thanks boats.net
Master Rebuild kit Thanks Ronayers.com
Oil and fuel filters
Nasty carb parts rack (I mucked up the pilot needle)

What I have done thus far:
Adjust Valve lash, tool scored from my Taurus SHO days
Rebuilt carb for the 5 time, Until I realized that I must break the rack, Polished and painted

Rebuilt calipers and Master, painted epoxy black
Rebuilt the switches and hand brushed the housing.



Current progress report
I didn’t like the Atari. But I like the 80’s idiot warning system. So I bought xs650 gauges. It wasn’t until 1 day before I got them I realized they were mechanical. Crude. I don’t like wasting money so I figured might as well use the XJ tach guts in the xs650 housing. So when I got them I had to separate the crimped ring/glass from the housing writeup here: (TO ADD SITE)
Once I had the guts removed I layed the faces on top to see if the scales and range of motion was the same. Well. I wasn’t lucky. So after a half bottle of wine and lots of slow thinking I decided to learn Photoshop. 2 steps back 1 step forward.

XS650 gauge




XS650 innards



My first attempt at merging the scales of the xj and xs came out spot on. Need to finalize the colors check the needle to the face then print. At the same time I am swapping to LED backlighting and indicators.



Well I liked the Atari thingy so much I started looking how I could nest it between the dual round gauges something like this.



But because the “brains” wouldn’t fit cleanly in between I opened it all up and started pondering how to do this. I knew if I could remote mount the brains from the LCD I could make it work. I stared probably the better half of an hour at the ribbon cable knowing if I botch the cable the whole shebang is now spares for other people.

The ribbon cable is copper trace laminated between 2 cellophane films the top layer is more of an adhesive protectant and the bottom layer is the backing/support. I have in the past tried to repair printed ribbon cables with varying degrees of success. Most of the time the solder iron heat melts the cable so you have to be fast.

Lucky me I can be fast with 20 years of soldering I always like a challenge.
If anyone would like to attempt the remote mounting of the LCD and have solder skills this is how to perform the surgery.

1st get your favorite adult beverage. Set this aside for now, This is your prize. We don’t touch this until this is over. Steady hands and clear vision.

2nd you must sand the top layer to expose the traces. I used 120 grit that was “worn”. Lightly sand across and up and down until you expose about 1.5 inches of copper trace. Hold it to the light and see if any top film is remaining if so lightly sand. It doesn’t need to be perfect plus you don’t want to sand to much because you will sand the trace right off.

3rd get your favorite solder iron with adjustable heat or daring use pencil irons. I use a Weller Soldering Station. I set the heat to medium low, enough to melt the solder but cold enough to not burn the solder. (burned solder changes from silver to a golden then eventually black) and fine gauge solder.

I get a nice small blob of solder on the tip and then would “tin” the traces. All I we are trying to do is prep the traces with a small amount of solder. Not a heaping mound. My method: I would lightly touch the tip across and along the traces until they were 95% tinned. Make sure you inspect each trace for inadvertent solder junctions between the traces.

4th prep the wire. I used ribbon cable. Floppy or old IDE cable is perfect. Separate off the cable a set of 12 wires. Next split about an 2 inches from the end the 12 into individual. Once split strip about an inch or so of the insulation.

4th (b) now we twist the exposed strand and tin the ends with solder.

5th step solder the wire to the traces. How I did this was get alittle bit of solder on the tip of the iron. I laid the wire on top of the trace and touched quickly the blob of solder on the tip, to the wire. The melted solder melts the previously tinned components and the joint is soldered. We are only talking like milliseconds to 1 second here so its fast. You will know right away because the tinned components will “flow together”.

Now do this 11 more times.

Once the ribbon is soldered cut the printed ribbon in half and do it 12 more times.
I am bad about taking picture but here you go.




6th step, Once done you need to add stress relief. My method was packing tape. I first taped across the newly solder traces then I fold the ribbon back on itself and taped that as well.





Whole process took me about 30 minutes.


7th enjoy your set aside beverage.

I have to still add a 12 pin connector between the new ribbons and modify the LCD to fit into a radioshack 4x2x1 project box.

 

It'll be interesting to see how these gauges pan out. I haven't seen anyone "salvage" the atari guages before. Most just get a whole different set up.

 

Nice, this is the hidden stuff most people won't see that I like to see or hear about being done to Bikes.

 

Very informative.
I'd say a Variable Heat Soldering Iron is necessary making those Ribbon connections.

If you could take "Close-ups" and slightly larger pictures to help illustrate the process more clearly, ... it would be very helpful.

 

I will snap some better photos tomorrow

Here is what I got done last night before my buddy called and wanted a beer.

The LCD is nested in a 4x2x1 Radio Smack project box. I had to trim down the "plastic" lcd surround to get it to fit. This current state is unfinished as I need to add 2 water proof push button switches, the Warning indicator and LED back lighting. I ordered some switches but they may end up being to big.



in between the xs650 gauges, Its super tight I still need to slot the mounting tabs for the gauge buckets.


And test fitted on the bike. I made a gross error in the cable exit location as it right in the way of the ignition switch. I may end up getting another project box.