Welsh Boy buys 750 Midnight Maxim

Took delivery on Saturday gorne, very nice condition too for a four decade bike.
Issue is no neutral light, tested bulb and it works so ruled that out.
I know about the saftey start regards side stand as previous owner of Seca model, on checking this bike, there is nothing of this by the side stand assembley. Reading verious sites they state this model was never made with it!

So, how do i get that neutral light working?

Another thing i found, under the main stand three wires have been cut and left! traced them up to connector block by the battery, coulours are 1. Green 2.Black 3. Blue stripe.

Bike starts/rides fine and all lights work.

Any help on this would be appreciated as always.

 

Well all XJ750 Maxim models should have a sidestand switch, the wire colors would be:

- solid Black
- Dark blue with a yellow tracer stripe
- Green with a dark blue tracer stripe

Our experience shows that the dark blue tracer stripe can be quite hard to be seen against a dark green wire, especially if it's old and dirty......

Bikes with a sidestand switch will also utilize a "cube-shaped" sidestand RELAY, which has a 4-cavity connector going to it with the following wire colors:

- Dark blue with a yellow tracer
- Black with a white tracer
- solid Black
- Red with a white tracer

There are 2 different "cube" relays on your bike, one is a starting circuit cut-off relay, and the other is the sidestand relay. The relays look identical to each other (besides the wording imprinted on the top of the metal cube) but function completely different from one another and although they will physically interchange on their harness connectors, the set of wire colors going to each differ and the relays operate in a completely different manner from each other, and thus are not interchangeable

https://www.xjbikes.com/forums/threads/the-ultimate-relay-switch-sensor-and-diodes-guide.27543

Very nice looking bike. Tank emblem appears to be the wrong size, but without a close-up it's hard to tell. Missing the mirrors? Fork gaiter boots have been added. Seat may or may not be correct, would need a better picture of the sewn pattern. Tiny little air filters may make tuning problematic.

 

Thank you for they reply, appreciated.
On your site i read:
Sidestand (kickstand) Switch:

Location:
- the switch is attached via two flathead screws to the left lower frame tube, somewhere either just forward or behind that actual kickstand mounting bracket.

Identification:
- cast metal housing with two or three lead wires coming off the housing, leading into bullet connectors (550 models) or plastic connector shells (650 thru 1100 models). NOTE: 1980-81 XJ650 Maxim and Midnight Maxim models did not use a kickstand switch, nor did the XJ900RL

 

The note about the Midnight Maxim models refers to 1980-81 XJ650 Maxim models, including the 1981 XJ650 Midnight Maxim. All XJ750 models had a kickstand switch, and kickstand "cube" relay, as did all 550 models, all 1982-up 650's, and all XJ900'ls besides the noted models. It was a safety issue, you do not want to drive off with the kickstand in the down position, it's a fine (but unfortunate) way to kill yourself..........

 

Looking on bottom rail alongside side stand there is no referance of ever being one, all paint original and smooth!

 

Larger picture

 

Very odd..........is the 4U8-xx cube relay present? It would be located under the left frame triangular side cover, on the plastic regulator-rectifier mounting plate, held in place with a rubber "strap". There would be a 4-cavity white connector shell with the aformentioned wire colors in it.

 

As mentioned, i found wires cut further back just hanging, black,gree,blue/stripe.
Bike starts fine, select first run on centre stand, push side stand down, keeps running. Do you think wires have been got at!
It don't bother me, i'm 68 and been riding for over 50years, hardly going to pull off with stand down. What i would like to know, can i get the neutral light working again!

 

The bike was imported some two years back, not sure of history as quite a few new oe parts have been done.
Main stand/side stand. Complete rear arm. Chap i bought it from was second owner in UK, he owned it for just four month as health issues got better, he said bike came like this with added bonus (to me) fork seals done and new tyres. Worked prices out, all items done add's up to £818, i got a bargain as no mor MOT/TAX ----------- yay

 

Is this a Japanese market or US/canada? The Jap ones had some unique stuff on them.

sometimes the crap welding holding the side stand mechanism leaves company with the downtube, it has on my 650.
Neutral switch is under the crankase, single blue and white wire? It's a pig to get at, the exhaust is in the way.
Where are you in sunny Wales? The bike looks to have had some work, no way it's original looking like that, one change I would make is to bin those cheapo air filters - proper K&N s are better, especially if you can mount them as far from the carbs as you can.

 

Brain fart from someone who should know better from me - I was thinking about the low oil level switch, not the sidestand - sorry.
Interestingly, none of my 650s have a sidestand switch....
The neutral switch though is under the selector casing, guess its a contact on the edge of the drum?

 

US/Canada model. Quite a lot has been done looking at things, all to my advantage as costley if you can get the parts that is.
Just hope someone comes along and point to how i can get the neutral up and running, seems some idiot with new set of cutters decided to chop wires

 

Shame it came with airbox stripped out, never run a bike with pods! any advice would be good. Maybe change back to original set up next spring if i can find airbox for a good price.

 

https://www.xjbikes.com/forums/threads/xj650-neutral-light-wire-routing.124190/#post-623726

That thread has a good picture of the location of the neutral switch - it should be a sky blue wire attached to that terminal with a Philips head screw that shorts to chassis when in neutral.

If your starter is disabled when not in neutral (clutch out) then likely the neutral switch is working and connected, but not reaching the light. If the starter engages when not in neutral (clutch out again) then the safety has been bypassed, and likely some creative cutting / grounding to the sky blue wire to engage the starter cutoff relay, but didn't want a constant neutral light so they left that disconnected.

 

Are you referring to three different wires? It's a little confusing the way you have written it:

- a solid black wire
- a solid green wire, no tracer stripe?
- some color (?) wire with a blue tracer stripe, or, a blue wire with some color (?) tracer stripe on it?

As mentioned previous, the kickstand SWITCH should have these 3 color wires running from it:

- solid Black wire
- Dark blue wire with a yellow tracer stripe
- Green wire with a dark blue tracer stripe (and it's very hard to differentiate the dark blue stripe on a dark green wire unless the wire is clean and observed in a good strong light........)

 

That is a great picture, not only showing the switches (neutral and oil level sender) but also that funny clip that gathers all those wire sheathes/bundles together.

BTW, the neutral switch grounds thru the shifter drum itself (inside the engine); there is a little halfway-embedded "ball bearing" (or a BB) in the drum that stands proud (higher/taller than the drum itself) and which contacts a spring-loaded plunger inside the neutral switch when the drum is rotated to the neutral position. You would think that the grounding of that circuit is thru the switch body (to the crankcase threaded hole) but it's not; in a functioning switch, there is never any continuity between the screw terminal and the body of the switch!

 

Huge thank you to all who replied, appreciated and going to have to live with it as is.

Spoke with the first keeper (UK) last night to shed some light on things, he turned out a real gent and went through everything he'd done in the eleven months of ownership. Second owner had it for four months before myself, he loved the bike but developed a hip problem, he told me he never had chance to ride the thing, shame life takes a horrible turn like that.

First keeper bought it from West Country (UK) bike importer, it was a mess but he like's a challenge, he has various collection of bikes, mostly British so he was dipping his toe in the Jap market. He sold as per picture as the bank balance was looking bad fast, over £2,000 he spent getting to this stage, not including the purchase price. As per all projects when you sell, never see your money back and it went for a huge loss.

Asked about missing safety wires under clutch lever and kickstand, that’s how it came, also the neutral light, no and the missing air box - all came as is.

My huge bonus from all this, rear swing is New complete with bearings/oil. New stands, side/main. Forks compleatley rebuilt. New tank. New handlebars. All these parts were also powder coated. New set of tires, he said they cost alone £300.

Lifted one of the fork gators yesterday for a look, chrome tube is like new, fair do’s to him.

As for the cheep air pods - bin job get some quality K&N,treat myself as iv’e saved a fortune. The XJ600 (stop gap) I had when I joined here I sold, this one cost me £150 more than what I got for it----- happy days.

 

The plunger on my neutral switch was worn Ken. Replaced it all sorted. Usually it's wiring though. Still got it just thought mabe it's just gummed up .

 

This is not my first dance in XJ range but never owned a Maxim before. All my past XJ’s were original air box set up. Having taken delivery of this model that came with pods you see in aviator and reading the NO’s on here I have decided to go back stock item, the deciding factor was pulled plugs last night and black sooty was result.

Polite question,will air box from XJ750 (UK) models fit this bike! Or point me in the direction as to which one.
Kind regards as always

 

Silence is a Bitch!

 

Was the xj750 maxim ever a UK model? I know the 650 wasn't. There don't seem to be many around..
The carb spacings are the same as the 650 maxim - Ooo, this makes the assumption that YICS and non are the same spacing, my 650 maxim JDM is non yics.

 

I may be wrong, but it looks like both the 750 SECAs and the 750 Maxims here in the USA used part number 5G2-14401 for an airbox

 

You are right Dan.

https://www.cmsnl.com/yamaha-xj750-maxim-1983-d-usa_model8927/partslist/B-02.html

https://www.cmsnl.com/yamaha-xj750r-seca-1983-d-usa_model8926/partslist/B-02.html

The part numbers match for both machines here.

 

Few questions!
O/E front discs with 5mm thickness left, how thick would they have been from new!
Speedo showing 40k +. Clock has both kph & mph, North American model, which speed type do they use!
One for you cleaver people: How many miles should clock show if original item discs have 5mm thickness left.

Look forward to your answers.

 

5mm is like new l believe Ken.

 

If kilometres is along the outer edge of the speedo and the larger numbers then the odo will be counting kilometres

 

Thanks Simmy, turned out to be MPH.

One for the experts:
As per thread some electrics were cut/discarded regarding clutch/side stand safety features.
Managed to source both items through D&K Spares for this model (in post as we speak).
1. What colour wires fit where for the clutch!
2. Same question for the side stand.

 

Black yellow stripe, blue yellow stripe clutch handlebar switch.

Black wire no stripe and blue with yellow stripe sidestand switch.

 

Thank you Franz
Your 1st answer - is the power connection for this inside headlight shell!
2nd answer - is the connection for this other side of side-panel!

 

Yes l believe its inside the headlight shell. Yes it should be on the same side as the sidestand up near the top of the battery housing. On my 900 they are so the 750 should be the same.

 

Bike is taking the piss! managed to buy side stand switch for this model, fitted it, is there someting missing! when stand is lowered nothing makes contact with switch. I'm sure on my Seca the stand pushed something against the pin.
What's missing i'm all

 

Is it the same part number?

https://images.cmsnl.com/img/partslists/yamaha-xj750-maxim-1983-d-usa-electrical-1_bigyau0852f-7_5f5c.g

Yamaha
product number:
5G28256601

 

Just popping by! been busy putting all the wrongs to right on this old boy. One word (prick) whoever messed with air system by chopping items out and placing them stupid crap pods, was he/she/they trying for a drag bike as that is the only time they work - flat out!
Anyway, original airbox sourced in Finland, four new intake rubbers direct - Japan (5 day turnaround) now that is service. This was my winter project but recovering after a nasty fall so unable to ride. While recovering, made a start putting a wrong - to - right and make this bike breath again. Only manage short times in garage due to pain, will pop some pictures up as and when.

 

Airbox in and NO tilting engine or starter removal! even carb's left in situ...........

Call it - Welsh Wizardry!!

Not shy of 70, owned bikes over fifty years and always had the gift of looking at what's the easiest way and seeing the end result finished in my mind before attempting to work on it.
Now the job of buttoning everything up nicely over the coming short times I can work due to the fall I suffered.

 

Explanation of pictures:
A. Bike arrived in the UK wearing these stupid filters! The 1st UK owner spent over 2k on refurbishing many parts over 10 month ownership and ran it afterwards with them - odd as he's like myself, a very experienced bike enthusiast with a plethora of bikes in the garage. He sold this on as it was eating his savings like a hungry bear. I'm the 3rd UK owner, 2nd never rode it as his hip problem got worse, he lived quite close so zero miles was put on with the bonus it was kept in a lovely posh garage until i purchased. Both said it needed carb's tuning as popping on acceleration, knew it would with CV carbs.
B. Put bigger pods I had kicking about on while I sourced an original airbox, these were always a no-no.
C. Found an original airbox online and waited for delivery, good condition, rubbers are a bin-job so ordered new originals from Japan, great price with 5 day turn around, time to clean it while waiting.
C1. Getting things ready for my plan!
D. Cut around the back section marked with an arrow, screws you see are for fixing temp holding plates for later in process, separate both parts.
E. Things are tight but with gentle persuasion and persistence in it goes, no removal required of carbs/starter as this way was thought through thoroughly beforehand.
F. Airbox in place complete with back section and held in place with temp fixings as i plastic weld everything into place.
G. Finale stages, just waiting on delivery of the air filter which came and all fitted as it should.
H. Crankcase pipe all plumbed in to make this old boy breathe properly as intended.
I. All complete, these new rubbers were a joy, all nice and squashy for the painstaking operation of setting them in place.

Conclusion: All running/breathing correctly as CV carbs were intended to do. Now the weather has changed for the worse back here, bide my time for a good ride as my old bones don't do cold anymore.

 

Wow good project to get the air box back in there. Well done.

 

clever approach.
welcome to the XJ midrange gain!