Pumba the XJ750 project

Decided to put up some of my current project because soon I may have some questions.
Last year I bought a XJ750 as a project bike.

And stripped it down

sandblasted and zinc treated the framed, then powder coated

started putting it together


found the parts guru on here

decided to rebuild the carbs


buy some cool bits

Then I got to the point of posting my progress

 

That's pretty much the same shape mine was in when I bought it. Takes time to get'r running, but worth the effort (for me anyway)
Keep us posted on your progress. Looks like your headed in the right direction!

 

What a couple of before and after pics! SURE looks like you're doing it the right way. Looking GOOD...

skillet

 

Good work sure heading the right way keep us posted!!!!!!!!!!

 

WoW! Lookin good! What bars are you runnin there?

 

The bars are link to ebay site

Doing some reworks to neaten the wiring soon and intergate the Koso dash.
Currently machining up headlight brackets.

Pics of the switches that I will be using


Tank is coming along

 

LIKE th tank, why th $5 note?

 

The $5 note?
For scale, both the Koso instruments and the lights looked smaller than I expected when I bought them online. They both look better in the flesh than the sales ad which is good.
I did get the it running to make sure the engine was intact before stripping down.
running

 

where did those switches come off of.... I like them... any links to buying some like that... i am after a chrome set of switches and finding them in england is a right nightmere... but I am sure there must be someone in the usa who sells that kinda thing.

 

darkfibe'
Where did you get the handle bar sitches? Looks like the right hand has cruze control built into it. I can't wait to see how everything comes together with handle bars and switches.

 

Looks good, that is a SWEET tach/speedo, and light set up.

 

is there a choke lever on that left control?

 

jonrms, you try mikesxs? they sell chome switches that will work, but theres not choke cable

 

Got them from Ebay just search for Yamaha royal star handlebar switch.

 

Will be using the extra switches for controlling the vid cam

 

Not running the choke cable. Will make up a manual control directly on the carbs. Carbys will only be on the bike until I get it on the road, then comes EFI

 

Finally got some more done.
Carbs finished


Exhaust on and spin on filter conversion


Resoldered the ignition unit and made the harness seperate from the main harness and replaced the coil connectors with sealed weatherpac ones

And gave it its first run up since the project started.
http://www.youtube.com/watch?v=pUDY8t_p8h8

 

very nice

 

Dude, what are those guages off of? I saw some like that about a year ago and have been looking for one since.

 

Subscribed...

I'll be watching this one. I just signed up to the site, because I'm debating picking this '83 up next week when the guy gets back from vacation. It's $600

 

uhh that is the cleanest bike i have ever seen for 600

 

sorry..don't mean to hijack. It IS nice looking. I think I'd be crazy not to pick it up. The same guy just sold a good looking '77 cb750 that I was a day too late on, because I couldn't get off of work. I've been emailing back and forth with him non stop for days. Just a cool 50 year old dude that really loves bikes. He also has an '83 gs1100e and xs1100 that look sweet, but they aren't up for sale.

I'll start my own thread when I get this in the garage. I want to chop/bob it. Not 100% sure on the direction I'll be taking, but I'll be reading a TON on here to help me figure it out. Great site.

Sorry again for the hijack

 

The gauges are Koso...
Can be found here koso

 

Found time to work out the wiring connections for the replacement bar switches, and fit new sealed connectors.



Love the way they look too


Now its strip down the wiring and audit out some of the crap and replace most of the connectors.

 

That's wiring hareness looks like a bowl of spagetti gone wrong!!!
Those weather-pack connectors are the answer for sure. Using them along with die-electric grease and your connections are sealed tight.

 

Ok
In the middle of the wiring, and noticed no headlight relay, so I will add one.

Will keep the neutral and clutch switches operational, but get rid of the sidestand switch.

Changing the flasher unit to electronic, so I can change to any globes or LEDS at any time
Next question.
My new switches have a hazard light switch, should I keep it as a spare switch or wire up hazard lights?

 

I don't see a need for hazards, but I guess that would just ber personal preference. I personally wouldn't use it.

 

Oh, and I have a '90 gsxr 1100 with a rats nest for wiring. Would you like to come redo mine while you're at it? It's looking great.

 

For those who are trying to tidy up behind the headlight area, today I
went from this;



All that junk was removed/edited/modified


And now we have this;


Indicators are not terminated yet.
As soon as I get some tidy bullet connectors for the indicators and a changeover relay for the headlight its test on the bike time 8O

 

Is there a fuel gauge with that instrument cluster and will if work with the sending unit from a Seca tank? Just wondering> Thanks!

 

Yes there is a fuel Gauge in the instruments, can be programmed for a 100ohm or 510ohm sender.
I will probably be slightly modifying the sender to get it to work correctly.

 

Great! Let us know if/when you get it to work then. I searched high and low for a gauge that works with our senders, and ended up finding one on line (automotive kind - $25~) But haven't got it just yet. Trying to figure out where I can mount it so it's not so goofy looking on the bike, like the one I have now (mounted on the handlebars)

 

Did a mock up of the wiring and gauges on my second start up.
The gauge reads opposite, so after a quick reversal of the internals of the sender it was time to test again.
Full = full
Half = half
Empty = quarter

Research continues 8)

Today I also got the final shims and finished the valve clearance and balanced the carbs

Wiring is almost there.

Here is todays run up for those interested;
Pumba runs

 

Alright....I'm not too crazy about the sound of the bike. I'm glad it started and it's all working great, but what are some popular exhaust mods to make these things sound a bit meaner?

 

That's coming along great! The gauges and controls look excellent.

 

I agree the exhaust note is not inspiring, but after it is registered and on the road I will be considering changes. The project has many months to go

But as for unique exhausts, Pumba is a long term project with multiple stages.

Pumba MK II is the bit I cant wait to do!

Spent time today after work machining brackets for the dominator headlights

Could not find any headlight brackets that I liked, so I decided to make my own :!: 6 hours labor later i'm halfway there.
I sure hope they turn out the way I imagine them in my head :wink:

Fuel gauge update;
Sender will not work as is with the Koso gauges, although I can get a full reading, but tank empty is 1/3 on the gauge. Through my contacts (automotive instrument tech) I have ordered an internal winding to suit a Honda that I will try to convert into the XJ750 sender.
I expect this to work, and will document the progress. I am not sure others will go to as much trouble.

But with this project, the enjoyment is in the journey, as well as the destination

 

"But with this project, the enjoyment is in the journey, as well as the destination".... Like any good ride should be, that's not merely from A to B.

 

Version 1 of the headlight brackets. Not that happy with them. Still need to round off a few edges and polish up, but they did not turn out anything like what I visualized they would.
Being multiple pieces allows later changes :?

 

The Koso instruments have 2 fuel gauge options. The options are to suit either a 100ohm or 510ohm sender. Evidently 100 ohm is common Yamaha and 510 is common Honda.
The first thing I noticed was the sender read the opposite way, and this was quickly fixed by reversing the senders internal resistor. This gave me a Gauge that read full correctly but read empty at 1/3 tank level (510ohm setting)

Over the last few days I have rewound the sender and shortened the resistor wire to convert it to be a 100ohm sender. Testing will happen this weekend and I expect it will perform correctly (resistance tests are ok)
If it works ok, is it work putting up a separate how to? There seems to be a few people looking for alternative gauge options, and modifying the sender to suit a more common yamaha gauge may be of interest?

 

Ok The Koso dash's fuel gauge requires either a 100ohm or 510ohm sender to work properly.
The XJ750 is 320ish ohms and also reads backwards.
The first mod is to remove the actual windings by bending the tabs open;



And then flipping over the windings so the ground is at the other end.

After trying this connected up to the gauge full was spot on, but the tank was empty when the gauge read 1/3


Time to go deeper into the problem;

Resistor windings were unsoldered and removed


And then unwound. Resistance was checked along the length, and it was cut at 110ohms



Then carefully rewound.
First resistance test showed problems, but once the path the wiper runs on was scraped clean to remove any insulation, it now works perfectly.
Next week I will do the same to my spare sender

 

Whoa! My head hurts just thinking about going that deep. Looks like one of those long winter days out in the shop for that kind of trickery to be accomplished.
Thanks for posting. That's one for the future tinkering when I'm all alone and looking for something to do in the off season. Atleast a good option now anyway.

 

The best things about projects is the ability to change ideas as you go along, things can evolve, and you can try something and hate it and move on.
The rear section of Pumba is currently on hold due to the fact my ideas look pigdog ugly :lol:
Plan b may evolve from it and work. :mellow:

I had a friend with a lathe make some spacers for the bars.
This was required due to my choice of switches. They were for fatter cruiser bars, and I didn't want thicker bars because it would mean different saddles and brake and clutch mounts.
Gav has machined up some nice spacers that fit the bill very well

At last a final fit up of the bars and switches;


The indicators are just sitting there for ideas, and now I have to design the Koso dash mount.
This is not a simple matter due to the fact I am considering adding a GPS, but I'm not even sure I want it.

Bar ends ordered today from Ebay as well as mirror mounts.

This week I have to decide on front brakes, almost certain to go with early R6/R1 complete system

 

Todays effort
From template, Koso Bracket and alloy plate;



To XJ750 koso mount


Very happy with the outcome


Single wiring plug for the instruments...

 

looks an awful lot like what I'm about to do.
I think I'll crack open the new gage cluster and paint in the 10k redline.

 

dang man, that's bad ass

 

Looking great! Very professional and clean.

 

Very nice looking project - keep updating. Thanks especially for the resistance info on the fuel level sender unit - I'd like to swap out my gauges eventually, and love the look of those. Any modifications necessary for tach? Looks like speedo reading can be changed in the unit to account for various wheel sizes. Also, does the panel happen to have a thermometer on it (air temperature)?

Very nice work.

 

The tach has options for coil neg or sensor pick up, and can be configured for dual fire coils and multiple cylinders. Dash has 2 temp inputs and I will probably use one for oil temp and one for cylinder Head temp. You could use them for any temp with the right sensor.

 

While waiting for brake parts I went back to trying to paint. And I've had it ! By the time I get the finish good enough I will have spent heaps on
spray cans and spent 60 odd hours to achieve an inferior finish that will wear off as soon as I put a tank bag on it.

Thats it, the towel is thrown.

Time to put aside a budget to get the paint done properly.

However the color scheme I have tried seems to work for me, and the look i'm trying for.

I decided to fit up some of the bits for some photos, as Pumba is getting the stripped back down for the front brake upgrade (R1 brakes FTW!), diff overhaul and the change to the different style rear wheel.

So the current look (which may change upon reassembly).





I lowered the instrument mount as I didn't like how it sat too high.



Of course the switches touch the tank


Now its strip down time again

Believe it or not, I do want to get Pumba on the road, but the amount of things I find to recondition/upgrade is amazing.

 

Looking good! and Shiny forks!
Do you really need to turn the handlebars anyway? I see lots of arc shaped rubberized marks on your driveway, in your future!