First Cafe Racer Mod! 1983 XJ750 Maxim

Nice video.

Well, the 15R casting on the lower fork tubes is the proper tube for both the 1982-83 XJ750 Maxim tube. The long "dipstick" on the bottom of the cap bolt indicates that it's from a 1982 750 Maxim model (as does that "shared" air hose system), the 1983 models did away with that adjuster stick on the bottom of the cap bolt (a great idea, but rather finicky to use).

So I think that someone has simply replaced the proper upper cap bolt plastic cover with ones off some other, unknown-to-me (is that a known-unknown, or one of those elusive unknown-unknowns?) model. The top cap covers are somewhat interchangeable between many models.

So I'm going with "1982 XJ750 Maxim forks" for $100, Alex..................

 

Just to make sure we have the right info Len, it has Y75R, in case there’s a typo, I took the photo when it’s dark so it’s not the greatest quality..
I definitely agree with you though, everything I’ve seen so far points to an 82 Maxim 750!

Apparently a damper rod wasn’t needed as I’ve seen in the forums
I removed the top springs.
Removed the drain screw on the bottom.
I was able to separate the upper and lower forks with a simple tug!
The piece that the rod fits into appears to have been taking damage and needs to be replaced!



I’m actually quite surprised how easy this really is compared to others I’ve been reading about!

 

Anyone recognize this Spindle type?
Len doesn’t recognize it.

 

You know, the more that I think about it, it may be that someone has swapped XJ1100 forks (or, at least the guts of them) into those tubes. The XJ1100 models also used that "shared air-assist" feature, and they use a goofy taper spindle somewhat like the one you have shown (the semi-threaded hole is the clue).........the XJ1100 forks retained the damper rod via the oil drain screw, coming in from the side of lower fork tube, and threaded into the taper spindle. But that one on your bike also looks like it's been modified.....the V-cut on one side.

XJ1100 models also used that long skinny rod embedded onto the bottom of the cap bolt. Only thing is that the XJ1100 used 37mm chrome tubes (750 Max used 36mm) so those air joints for the hose wouldn't fit properly.

It's all very confusing........

 

Hmm, maybe a previous owner just ordered that Spindle part to piece together these Franken-Forks!
I wiped off and inspected the Spindle since you mentioned it may have been modified I think you’re right, it’s definitely machined!
There’s a “finish” difference where it’s tapered, it’s a little uneven, and impact grooves from the internal surface of the Lower Fork Tube.
The Spindle does have about 1 mm of free play inside the lower fork tube.
I measured things in case that helps!



The culprit= wrong Spindle for the bike!!

Once again Len, your knowledge is incredible!

 

Looks like '82 750 Maxim forks, but I think someone swapped the insides somehow. I've never played around with swapping for internals, so I don't know. It's just a guess., or maybe swapped tubes.....etc......

 

Eureka! I went and pulled a taper spindle from an XJ1100 (it's called an "oil lock valve" on the 1100's for the uber-curious) and darned if that ain't it...............although, someone has modified the one that you have, probably to make it fit. I mean, since it didn't fit, you just use a bigger sawzall, right? That's always what I do when I'm messing around with brakes and suspension and other bits that my life possibly depends on.

So, you need a taper spindle, and perhaps a dampening rod, and God-only-knows what else......

 

Or just get the correct forks

 

I ended up buying '82 forks on eBay, got the rebuild and a new tube from @chacal, everything is looking REALLY good, in a couple days i'll have a photo working picture of the front end!

Anyone know what the Ohms are on a 1982 Seca 750 gas meter sending unit are?
I know it's random but I'm double checking before buying a gauge and I would like to go digital since wired applications in MPH are hard to find or ridiculously expensive!
Also my 83 750 Maxim didn't come with a gas gauge and I'm guessing a digital speedometer/ tachometer would bring the electricity needed within a display.

If I remain analog, whats the ratio i'm looking for with our speedo drive?

 

600 ohms seems to ring a bell

 

HCP683
OEM Fuel Tank SENDING UNIT 5G2-85752-01-00
same as 750J Maxim, but arm has a reverse bend to it
Full = 25 ohms
Empty = 300 ohms
Applications:
XJ750 Seca

 

So far this is looking to be the top contender!
https://www.amazon.com/gp/product/B076KMJ525/ref=ox_sc_act_title_1?smid=A2KZ2NFQTEZSE3&psc=1

Anyone with experience using this one or switching to digital speedometer? I saw someone here is using an Acewell

This is one is nice too and uses more space on the display but $300 on a gauge is steep!
https://kosonorthamerica.com/shop/motorcycle-mx/tnt-04-multifunction-meter/

I'm trying to avoid those nice looking but cheap Chinese ones, although perfect design, they're outside of my qualifications!
https://www.amazon.com/IZTOSS-Speed...coding=UTF8&psc=1&refRID=9E2NTR8HVM8R3TW7QRQ1

 

i use a old acewell from some dirt bike.

 

Do I need some sort of limiter/ regulator for an LED headlight?
Headlight I purchased:
Power: 30W(Low Beam),45W(High Beam)
Lumen: 2800lm/Low Beam,4000lm/High Beam
Working Temp.: -40+85°C
Life-span: 30,000hr
Size: 5.75inch
https://www.amazon.com/gp/product/B071Z6JQCF/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Brackets were horrendous so I bought these if anyone was curious:
https://www.amazon.com/gp/product/B00WXZQNCE/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
Incredible quality!

 

Depends on the headlight, many Led lights have the resistor built in. May need a different relay if you are using the stock wiring harness. You definitely need a new and regulator/rectifier if you are upgrading to a lithium ion battery like the anti gravity or ballistic. The charge point is lower ~14.2v compared to stock lead acid which requires ~14.8. Don't want to fry your expensive new battery. Rick's Motorsports can make you one.

 

Awesome, I was suspecting that they may have the resister built in.
I think I'm going to keep the stock acid battery and air box set up, I'll just cover them up!
So if I plug it in I'll be OK?
Electrical is where I get nervous!

I've been busy taking care of my uncle for the last month so I've barely been able to touch her, I'm excited to upload a photo worthy update soon!

 

I would definitely check the specs of the headlight you decide on, but they are generally plug n play. Look for one that is rated for use on a 12V system. Almost all of them are. Avoid eBay, you get what you pay for.

 

Update on the project now that I’m getting to it again!
I’m currently on the painting phase for the gas tank and front fender, removed all paint, did a little Bondo work, put 2k Epoxy primer to seal it, sand, another layer, sand with 320 grit.
Going to do Filler Primer, maybe 1-2 layers to fill in any pits or scratches and sand again.
Hit it with 1k base coat, 2-3 layers.
Then 2K clear coat, 3-5 coats (because it’s the protective layer) then 1500-> 3000 grit wet sanding to rid of the orange peel!
I already use Caswell Epoxy gas tank sealer on the inside too!

 

Anyone have a wiring diagram for the stock gauge cluster?
I need to figure out some of these wires on the stock setup.
I labeled their uses and figured out majority of them being ground
If anyone is interested, I purchased an Acewell digital gauge with a speed sensor adapter, also trying to "add" a fuel gauge from the 82 Seca tank I swapped out on the Maxim.
(Maxim didn't have a fuel gauge but the Seca does)
Acewell gauge:
http://www.acewell-meter.co.uk/Acewell Speedometers/ACE-MD52/MD52-253.htm?action=full&id=198
Acewell speed sensor adapter:
http://www.acewell-meter.co.uk/Acew...s - Cable Drive/ACE-S12.htm?action=full&id=25

 

Shouldn't be necessary.........

Which cluster (what year/model bike?) and/or specifically, what in particular do you want to know?