DKW's Midnight Maxim 750

This is my last acquisition, in fact a gift from my wife, an old Midnight Maxim '83. The bike actually is in a poor condition, but will be partially restored, partially customised.


The engine run fine, the exhaust is ok (but not stock), the rear shock absorbers are broker, the fork is rusted, and front ball bearings are broken too.

 

those forward controls terrify me.

 

DKW,
Welcome to the camp!
Looks like a really nice project.
Let me be the first to say it: Keep the airbox!

 

Those forward controls will be replaced with a pair of Virago 535 modified forward controls, and everything will be painted in black, excepting the chromed parts.
The airbox will not be changed or modified, i have more bikes and all of them have factory airbox.

 

Password accepted. You may enter the clubhouse.

 

Not much Midnight stuff is there.......how do you know it's really a midnight?

Looks like a regular 750 Maxim that some tried to start a MM clone project

 

All the things I know, the fenders are not original, the exhaust is not from Maxim model, the engine could be swapped. The bike was painted by the ex-owner after some little crashes and have some improvisation, like forward controls or electrical circuit

I checked the VIN at dissingermoto,com, the identification number is 22T100506.
VIN INFO:
World Manufacturer Identifier:
J = Japan, Y=Yamaha, A= Motorcycle
Vehicle Characteristics
22T00 = 1983 XJ750 Midnight Maxim Canada
Check Digit:
4
Model Year:
D = 1983
Assembly Plant:
A = Iwata City Production Facility
Serial Number:
100506 is the Serial Number.

 

Ok, good! You did do your homework. 100 points for you

Now- you have a LOT of homework to do. The Midnight Maxim had a lot of special pieces that you are going to need to find. In YOUR case, pretty much everything except the handlebars and the seat.

Just about everything else on your bike is NOT Midnight Maxim.

We're here to help you.....

Dave f

 

I know, I found on ebay many parts, but the shipping to my country will ruin me.
I wish I had the possibility to fully restore this motorcycle, but will took too much time, so, will become an custom project.

 

How the heck did a Canadian Max get all the way to Romania?

 

Thru Holland, where was registered in 1991. The biggest market for non-european models, imported from United States or Canada.
If you are looking for something different, search on speurders.nl.

 

Back in early 90's containers full of bikes where being shipped out of Vancouver to points in Japan,Europe and the UK. As a parts guy then, I sold truckloads of parts going with them. And with export rules being sloppy many of those bikes were stolen.

 

Shame your so far away I have an 83 xj750k that was in nice shape until engine went Bang

 

So just to be clear T00 is midnight but he states serial number starts T100?
I have 2 xj750's both start 22T-000

 

22T

 

Looks like Len may need to clarify---

 

Hi Dave
In dkw 's post after you asked if it was a clone ,he listed 22T-000 as midnight instead of 22T-100 that's what got me wondering what was what

 

Well, there's confusion on len's list, too, as I'm looking at it, so I sent him a message to check this forum.
Also, in the breakdown, the op does show 22t100........so, Len can sort this out

 

Where I come from, midnight is 24h00.

Sorry, bad attempt at humoring.

 

Apology accepted

 

According to Len....

"His bike is a 22T frame code with a serial higher than 100000, hence a MM.......

Len"

 

Yes there seems to be a disruption in the force somewhere..............I'll have to go back and check my source documents (if I can find them!).

But a 22T frame ID code with a serial # higher than 100000 should be a Midnight Maxim, although some of the VIN's that I collected over the years from various sources (including eBay bikes for sale) indicates that some MM's may also be in the "less than 100000" rnage of numbers:

JYA22T00?DA000208 (Canadian MM)

JYA22T00?DA000131 (Canadian MM)

JYA22T00?DA110217 (Canadian MM)


Note that the MM's with serial numbers lower than 100000 also had a model ID code of 22T (rather than the 33U code). It could have been than Yamaha wanted to "experiment" with creating a few MM models and they carried the same MODEL ID code as a regular Maxim (which is how it was done in the USA), and then seeing that they were popular "enough", then gave them their own model ID code, and started the serial numbers over from 000101.........

It's hard to get definitive info on low-production bikes, especially when the parent company doesn't have or won't release such info.


COUNTRY: CANADA

MODEL NAME: XJ750MK
STREET NAME: 1983 XJ750 Midnight Maxim
MODEL ID CODE: 33U <<<<<<
FRAME ID: 22T
SERIAL NUMBER STARTS AT: 100101

MODEL NAME: XJ750MK
STREET NAME: 1983 XJ750 Midnight Maxim
MODEL ID CODE: 22T <<<<<<
FRAME ID: 22T
SERIAL NUMBER STARTS AT: 000101


Of course, you will never see a MODEL ID code anywhere on the bike----you see the FRAME ID codes on the frame----and perhaps the only place it is ever seen was on the original sales invoice?

Luckily, in this era, the FRAME ID code = MODEL ID code 99.9% of the time. The anomalies tended to occur on low-production bikes made for small markets....for which a Canadian MM would certainly qualify as!

 

BTW, one other clue(s) that I would look for is the small, script (cursive) emblems on the GAUGE CLUSTER HOUSING and the similar emblem on the rear seat PANEL that says "Midnight Maxim" (script, "stacked" design with the word Midnight above the word Maxim". Even if the emblems are missing, there should be outline of where it was.........

And of course any other gold items that are unique to MM:
- headlight bezel
- front fork emblem (gold lettering) on black emblem, rather than black letters on a chrome emblem)
- gas cap
- swingarm bolt covers
- rear brake drum (black with gold inset stripe)
- footpeg brackets (black with gold inset stripe)
- rear grab bar (gold)
- engine case covers (black with gold recessed lettering)

- the seat would be of a unique design/pattern (can't see it in any of the images), but as Dave mentioned, that is an easily substituted item from a donor bike.

 

Thanks to @chacal for providing the Encyclopedia of Things For Which There Is No Encyclopedia.

 

In the sale announcement it was passed as a Midnight model, if the bike isn't the Midnight model, I assume this situation.
The front fork emblem have golden lettering on black plastic, the side covers was repainted, but they are black with golden edges/contour. Rear bar grab was repainted too, in fact, the whole bike was painted using cheap materials.
The bike have many parts swapped with non-Midnight model, the ex-owner had several accidents with this motorcycle.

Btw, where is located/stamped the engine number?

 

Engine # is stamped on the right side above the clutch cover. There is a flat spot on the block, right near the oil filler and clutch cable support. But, if the engine has been swapped out, then the engine number is a moot point. The number stamped into the head tube is the important one.

 

The seat is definitely MM, the handlebars are MM, the front fork emblem probably is....the tail light assembly is, unless it's been painted black. The passenger foot peg mounts are MM. The shocks might be. The tank could be.

0therwise, just about nothing else is MM

 

Engine is definitely not MM, fenders should be black, carb hats do not appear to be gold.................

Need a pix of the gauge cluster from the front, the MM emblem would be in the flat area in-between the tacho and speedo round "pods".

 

Unfortunatelly, the cluster is not original, and all the badges "Midnight Maxim" are missing.

From the xjcd.org site:

 

Ooooooo...... Somebody dared utter "xjcd" here----- I'm gonna grab some popcorn and watch the boogeymen come screaming in along with the flying banshees.

 

Why? It's a blasphemy to say "xjcd" here? Then, i'm sorry, i do not want to offend anybody... I only used as a second source.

I know how they look, i spent many time on net and ebay searching for missing part.

 

Many moons ago, the disk which must not be mentioned caused devastating turmoils with the great gods of copyright. Many were lost, there was much suffering, and it shall not be resurrected with careless whisperings.

All this occurred before the time of Matti, but the legend has been passed from generation to generation.

 

The East Coast Partshoarder was there to witness it----

 

coffee spray

 

black headlight bracket is also a MM ppart unless someone painted it.

 

+1....saw it, forgot to mention it

 

Meantime, in my garage, studying the disaster... erm... this piece of art.

I must change the fork tubes, there are slightly bended, and replace all seals and ball bearings.
End of 1st chapter.

 

carb to manifold boots look odd to me

 

That's because the at least the one on cyl 1 is not the correct one for cyl 1. My bet is that #2 is the same......this is what happens when someone puts a non-yics engine on a bike that is supposed to have a YICS engine AND uses the non-yics carb-to-intake boots.

 

Exactly correct!

 

With the handlebar in straight position the front wheel have a slightly deviation to right side, both tubes have a flection right under the lower clamp.

Btw, what is the connection between two threads with different topics?

 

Meantime...

 

So, the bike is a totally crap, the engine was swapped with a 650 cc...

 

After a while...


Question, what is the difference between 650 and 750 crankcases (Maxim engine)? The internal parts are the same, excepting upper parts (pistons, cylinders, etc)?

 

The 750 is a bored and stroked 650. The cases are idenical, and the lower end internals are the same, except for the connecting rods.

There are some differences between the Maxim and Seca: The Seca has solid engine mounts, and a different shift mechanism cover. Othrwise the entire lower end of the engine is a direct swap.
I have Maxim cases (and rubber engine mounts) on my Seca, due to an oops while changing the alternaor chain guide a few years ago.

If you are swapping cylinders onto existing cases, you'll need to make sure that the heads and cylinders are both either YICS, or both not YICS for them to fit togther properly. The YICS status has no bearing on fitting cylinders to the cases however.

 

The actual engine is a 650 cc Maxim , 2 valves per cylinder, and my plan is to put all the internal parts in a 750 cc crankcases Midnight engine, and then, to change the rest of the part, cylinders, pistons, rods, camshafts, etc.

 

Why?
That's going backwards in terms of horsepower and torque. If you're doing that, it's easier to just swap the engine whole. Direct-fit; easy peasy.

All aircooled XJ engines are 2 valve.

 

Here, in Romania it's impossible to find original parts, except the brand new, so i bought from ebay a pair of crankcases from a 750 Midnight Maxim engine because the bike originally was fitted with 750 cc engine.

 

DKW,
Good luck on trying to find the parts you need. I am sure with dedication to your project you will do great! Keep us posted with lots of pics! If you have any issue finding parts let the board know and always check with Len from xj4ever (top right corner), he will always hook up up with the right part. I would hope he will make a deal with you for the shipping as well but I can't speak for him.

Very special to know that the xj lovers are all over the world.

 

OK. I see you delimma now. You still won't have a 750 cc engine though, if the plan is to swap over the top end from a 650.