82' 750 Resurrection

Hello everyone,

New member here and I recently acquired a 82' 750 Seca. 13K original miles.

This bike is going to need a ton of work and electrical is my main concern right now.

Currently the start button does not work, I believe the starting solenoid (it clicks, but no dice) needs to be replaced. Or there is a mess with all of the safety checks this bike has.

Jumping to the starter and supplying power to bike does result in turnover and spark! Kill switch is functional. Interesting that the tac needle goes all the way over when rocking the kill switch (in pics)

No lights work and if you noticed I do not even have the main headlight...just the aux. Wiring in the front is a total mess and there are tons of cut and spliced wires.

My main question to the group is where/how should I start? I've reviewed the electrical diagrams that others have posted and I believe I can follow it. I'd like to get the bike to turn over with it's current controls and see if she will run once carbs are cleaned and I get a stock airbox in. Previous owner put pods on and did not re-jet, so I cannot see it running properly.

I do plan on tearing down this bike entirely, but would like to feel better about the electrical. Future may be stripping down to bare minimum and removing the Atari entirely.

Looking for all suggestions and assistance to bring this bike back.

 

solenoid is a good place to start (ha ha ha) your going to use it a lot. a new battery and little charger is next. use just the charger while you get the wires sorted out, the sparks won't be as big as the battery would make.
it should start and sort of idle without a airbox. once you get that far, it's all down hill

 

Followed wires from the ignition switch and found one disconnected. Twisted that pair back together and tried to start her up via the button and all good! I will need to take the switch apart however since the connection is intermittent.

Seems my original thought of the starter solenoid was incorrect.

Yes, a new battery is on it's way and using a jump pack for power currently. Now that she turns over with the switch I feel a little better being able to sort out the other connections...

I already have the carbs apart and they need a deep clean. Intake boots also need to be replaced as all are dry rotted. I plan on trying to get her to fire up once carbs are cleaned just to make sure everything sounds good.

Excited for this project and appreciate all the input!

 

I just got an '82 750 maxim from a friend, she's in surprisingly good shape except for a few weird little "fixes" from the PO and the expected age related issues. I'll watch for posts from you about your build!

 

Check out k-moe and the "church of clean" for yr carbs.
Other than that these bikes are relativley easy to work on andfix have fun!

 

I am doing the same thing on a 1981. I've had some of the same problems, although, my starter selenoid was missing. My main head light didn't work until I eventually got it running. I am still having carburetor issues. Good luck! someone with mediocre mechanical skills had been working on mine also. That makes it more of an "adventure".

 

if your bike is an 81 seca 750 it has a headlight relay and headlight comes on when bike starts.
start your own thread so you have history on your repairs

 

starting your own thread will help you and us a lot

 

Well starting to tear carbs apart was fun...seems the PO broke one of the air/fuel screws...

Was able to drill it out (thankfully) and also confirmed threads are OK.

Carbs are beginning their "Church of Clean" journey by soaking in ultrasonic cleaner.

Also performed some initial compression testing:

Cyl 1: 115
Cyl 2: 130
Cyl 3: 130
Cyl 4: 100

A little worried about 4 but this bike will be getting a full tear down in the future. So if it doesn't work initially, it'll get fixed.

If you guys have any recommendations to a full carb rebuild kit, I'm all ears. Most of the jets are torn up and well the one air/fuel screw is no more.

Slides look good and the rubber diaphragms will clean up just fine

 

look in the catalog or send an emal to www.xj4ever.com fot your carb parts

 

i don't think that one's saveable

 

Thanks!

Next update will be once carbs are rebuilt and hopefully she starts!

 

a little jb weld and its fixed

 

Pic Heavy update!!

So I have been busy working on the XJ, cleaning and waiting on parts.

Took the carbs though the "Church of Clean" and really happy how they turned out. Brackets, bolts etc. were wire wheeled to be cleaned of rust and replaced if needed.

I will comment just before each photo for details on my process.


Initial state of the carbs:




Before and after pic of ultrasonic soak. Part simple green ultra and water. 50C for 45 min



State of the carb bowls before undergoing cleaning


Every single carb bowl drain screw was rusted and seized. Heat and a Dremel allowed me to get all of them out.


All air jets were cleaned with carb cleaner and small wire wheel


Installed new needle and seat. New main and pilot fuel jets, stock jetting. Carb floats checked and set to proper height


Carb rack fully assembled and performed a quick bench sync.


Drained the bike of oil and changed filter. Had to re-shape the filter bolt until my new one arrives. No metal shavings found!


I performed a fuel leak test, no issues. Checked all bowls for fuel. Mounted back onto bike and added new fuel line with filter (will change in future)



At this point I attempted to start the bike. Got one little cough and then nothing after, even with some starting fluid. I knew I had a weak spark to begin with and decided to look further into the plugs.

Seems the PO installed the wrong plugs (Autolite 403), so I picked up NGK BP7ES plugs today to hopefully solve this.

Bike fired up with a little help with starting fluid but could not stay running on it's own fuel. Again I suspected the weak spark, even though the spark was better than the other plugs, it was noticeably small.




So to conclude my testing for tonight, I went to the ignition coils....

Each primary coil gave an ohm reading of 3, which is over the 10% variance stated by the manual. There was my first clue...

Each secondary coil showed a open line, even removing the boots and going right to the wire I got nothing. Soooooo there's my problem.

Time to order some new coils and try this again. My guess is there's enough spark to ignite starting fluid, but when fuel takes over it's not enough

 

After reading some other posts on Ignition coils, I went back and measured mine again.

Primary coils are showing between 2.7 and 2.8 ohms. Reasonably within spec.

Fully removed all boots to get better reading on secondary coils and got 11 to 11.2 on each coil. Measuring with boots on shot up to 20.

So before I pull the trigger on new ignition coils, sounds like some wire trim and new boots would help....

 

Very nice post update! Keep them coming

 

have you adjusted the idle to keep bike running?
did you do a wet set on the floats to get them in spec a dry set of float height is a guesstiment of level just a starting point on the carbs?

that paper filter may also be an issue

 

Are you running the bike from the stock gas tank? That tank is all clean and no rust in it? Those paper filters are not the best for the motorcycle applications. I have one on my old IH tractor and it works fine. These bikes will need a little better filter most of use use the copper cone type or one of the cartage types that unscrew and you can replace the filters.

As stated above, take the time to bench test your carbs and check the fuel height in each bowl with a transparent tube. Only do this is you want to make sure the bike will run at it's peak performance and not starve the bike on wide open throttle. Bench testing the carbs off the bike will also make sure that all the "O" rings are not leaking and that the bowl gaskets are not leaking.

 

She runs!!!

I changed the spark plug boots and got better readings than before. I also opened the mixture screw a half turn more before trying to start.

Choke on and she fired right up! Idle is high as I think my bench sync was not done correctly. I turned down each sync screw a little bit, but I also believe that cylinder 2 isn't firing all the time. Checked the headers with temp gun periodically.

There is still work to be done but confirmed life!

I am not using the stock gas tank, made a external tank hanging from ceiling. Fuel flow is good and I will def be changing out the filter for final assembly as it's too big anyway.

My next steps include running the bike some more while adjusting the idle screws and re-check compression.

 

Nice well done! You can move the idle screw a bit but don't play around with the sync screws unless you have a sync gauge set up. You can do it by listening to the idle move but that takes a trained ear. Now that you know she is a runner you should check out the valve specs. You want it to sound like a well oiled sewing machine. There is always a little topend noise from a well tuned bike of this type.
No fuel leaking and none flowing out of the back of the carbs, that is great. Again well done.

 

Thanks! Yes won't mess too much with sync screws until it's time to do a proper sync.

My plan as it gets colder is a full bike and engine tear down. Rebuild the top end, new piston rings, check valves etc.

Then confirm my design for this build.

 

So I tested both my stator and regulator/rectifier which they both checked out OK. Some new connectors will be headed their way in the future.

Thinking ahead I am stuck between 2 options for wiring the bike. I already plan on not keeping the Atari and want to switch everything to LED.

Option 1: Keeping stock harness
-Remove Atari following "Atari Delete" for wiring of headlight and tail lights which will be a all in one LED bucket and LED rear lights.
--Unsure what exactly to wire for LED lights in rear and flasher capability
-Install new speedo/tac (Acewell)
-New fuse box (for safety reasons)
-New controls wired with new connectors to stock harness
-Possible different Reg/Rec for Li-Ion battery??

Option 2: Fully remove stock electrical - M-UNIT
-Wire all above fresh to the M-Unit with wiring kit
-Still possibility of needed a different Reg/Rec

I will note anything that is stock that I will not keep, I will post here for sale. I'm sure people are always looking for parts.

Let me know your opinions!

 

there is a thread on removing the atari and another for going led and having every thing work

 

Yep I have read both of those a few times. Good instructions. Wish the pics stayed as I am a visual learner, but can follow written directions

 

this has photos
https://www.xjbikes.com/forums/thre...-to-remove-the-rectangular-instruments.21580/

 

Purchased a used air-box and boots, not trying to fiddle with pods. Plus I kind of want to keep the stock look with the side covers flowing to the rear.

Planning on diving into the electronics tonight for labeling and removal of Atari unit. I will go the route of using the stock harness but also updating components/wiring.

I'd like to get things re-wired before stripping the motor out for deep clean and re-build.

Next update will include more pics!

 

ATARI unit has been removed and all wires labeled!!

I have new controls, speedometer and a fuse block coming in next week. I'll also be replacing most of the connectors since they are brittle.

Following instructions on "How to remove rectangular instruments" I have everything ready for a non-ATARI setup (hopefully).


Reading the LED post, I am still uncertain if the tail lights will need a resister put into place. My plan is to replace the stock bulbs (12v32/3CPB) with LED 1157 and also the license plate light.

I will do the LED flasher/SPDT install for the turn signals. Would these also require a resister?

Final question is about my model, is it typical for the 82" XJ750RH to have only one front disk brake? Unless I have totally labeled this bike wrong, or the PO swapped fronts at some point.

 

Search for the the tech topic “model ID and VINs” for how to identify what you have. I think the 650’s had one front rotor and 750’s have two. Not to say someone didn’t change it up

 

led tail light will triger the atari warning there is a fix for that
led flasher with led will be fine

you should have 2 discs up front is there a caliper mount on lower fork tube?
I also do not see air adjuster and connections at top of fork tube. that may be a 550 maxim front end

 

Yeah the ATARI will not be going back, so should be good to go then for LED.

So there is a caliper mount on the other fork tube. There is an aftermarket master cylinder installed, so possibly removed the other caliper and dual hose set up?

Going through the VIN identification, frame and engine are definitely 82' XJ750RH. PO could of swapped fronts or removed the other disk and caliper.

Can always add the other disk and caliper, which I may want to do. Just thought it was weird I did not have a dual set up

 

seca would have the remote mastercylinder maybe thats why it was changed.
if the atari is not going back on do not worry about needing resistors to any lights
you will want to check the size of the MC to see if it will support dual disc

 

Brandon, nice work I plan on doing the same with one of my winter projects. I will be keeping an eye on this thread...Thanks again for posting it.

 

Thanks guys!

I'll keep posting updates as I work through this build

 

Pre-Holiday update

So I've continued working on the electrical side and have made some good progress.

First I started with a proper repair on the start/stop switch wiring that the PO did who knows what to. No longer have intermittent starting issues:



Soldered all the connections and heat shrink-wrapped them.

My new fuse block arrived and I created all new connections and added solder (never trust crimp connections):


At this point I was comfortable with re-looming the wires and wrapped everything up:



For now I decided to go with a different speedometer/tac. Connected the corresponding wires that I labeled and hooked them up. Now upon turning the key, tail lights, license plate lights and the speedo turn on. I have a new inline fuse to install for the stock glass one:



I checked that the turn signals work and also it reads my fuel float from the tank.



Latest package to arrive are all new LED's for tail/brake and license plate lights:



I also found a weak ground connection and corrected that. Old semi-burnt connectors were replaced for the Reg/Rec as well as some others.

Needed to search Ebay for a used twist throttle as mine shattered due to brittle plastic. Found a OEM one for $12 and works like a charm.

My plan is to continue working on the electrical and get the bike started again. Next update will hopefully include a new headlight and I also need to replace the handle bars as they are bent

 

starter bolt missing or snapped?

 

Snapped....my fault. Good thing is it snapped with some material above the case. So I should be able to weld a nut on and remove it. Have to add that to my list of hardware that will be replaced

 

Interesting find on the Seca today. Wanted to get her fired up again after new wiring and I ran into my first problem again of the starter not working. Loud audible "Click" from the solenoid but nada from the starter.

I was able to jump directly to the starter sometimes but it was not constant. So after reading the post from tskaz: Replacing your starter motor brushes w/ pics;

I gave it a shot since rebuilding the starter would be good anyway. Well, it's dirty and gears covered in engine oil....not sure if that is right...bushings are shot and def needs a rebuild:


Few questions for those who have done this:

What is the best way to clean all of the "dust" if you will out of the magnet body? (Besides shop towels and elbow grease) Contact cleaner spray? (WD40 Specialist)

What type of grease should be used when re-assembling? (I have STP Multipurpose avail)

Parts that are not electronic based are set for time in the ultrasonic.

I will be ordering a rebuild kit just as tskaz and also a new solenoid as a extra precaution

 

Digging further into the front end, I found I need new forks or fork tubes. My other issue is my Seca only came with the one disk brake and caliper, not 2.

Been looking for a Seca 750 LH Caliper with no such luck (Besides one on ebay for $200+)

I purchased rotors from another member so now I have 2 as well as a Maxim LH Caliper.

Are Seca 750 and Maxim 750 fork tubes the same diameter? I was thinking of just swapping to a Maxim front end (Fork tubes, dual calipers/disk brakes)

 

I finished up rebuilding the starter motor, placed back onto bike and she now has no issues. Cleaned everything by hand or using parts washer. Used metal polish on the armature and commutator.





My new handlebars and grips arrived. I decided to modify the OEM throttle tube to work with any grip:

Cut off the end with the 4 tabs and enlarged hole to match opening:



Used a belt sander to remove all the ridges. Followed up with 400 then 1000 grit sandpaper to make the tube smooth


Thought I took a pic of new handlebars but I did not. It will be in another update.

New headlight came in as well. Mocked up the mounting to test power. DRL LED's work as well as each integrated amber turn. New LED flasher works like a charm, auto cancel does not work without the mod.

However I found there is no power running to the Y or G wires for the headlight. I need to troubleshoot this further as it could be the headlight relay...

 

For future wiring repairs it is best to use melt-seal crimp splices instead of solder and shrink tube on primary harness repairs. Race cars -never- use solder on any loom wiring. It's a wreck waiting to happen. A cold solder joint may not be visible when you've finished but it will break loose after repeat vibrations from the engine. If you begin having intermittent electrical issues down the road, re-do your solder splices. A crimp will fail only if the wire pulls out and that will be obvious.

 

What speedo did you go with? I will be doing close to the same thing you are. What size is that Virago you have?

 

Speedo is a super cheap Chinese one from eBay (also on Amazon). Took a chance as sticking to a budget for now and very happy with it. Search for this and a bunch will pop up: 12000rpm Motorcycle Universal LCD Digital Speedometer Tachometer

The Virago is a 92' XV750 that will get rebuilt once this project is done. It needs a top end rebuild.

 

that starter thinks it went to heaven

 

Yeah, I think starters get neglected despite how much heavy work they have to do on a regular basis. The OE starters are well made and just need new grease, bearings, seals and brushes every now and then.
CRC Electric Motor cleaner does a nice job of cleaning those electric bits up. Dries fast.

 

starters are overlooked. should be part of the plan just to make sure its good.

 

Bike has been stripped down!!

Took today and fully took the bike apart and separated the engine from frame.

Lots of surface rust to remove then paint from the frame, swing arm and exhaust system.

Been keeping a list of all parts I know I will need to order from Chacal. Bearings seem OK on the rear wheel but may replace anyway. New ones needed for front wheel and swing arm. New rear brake pads, front rebuild as well. Triple tree channels need to be cleaned, lubed and should be good to go.

Forks have been put aside as I am awaiting a set from another member which are in better condition then mine.

Most of the hardware I will be able to clean up, none seem damaged in anyway (besides the header studs and hardware good lord...)

New rear shocks will be purchased to go along with my "ideal" paint scheme.

Seems now I need to go into cleaning mode for these parts. Remove all rust, de-grease etc.

Engine will get plugged up where water should not go before being heavily de-greased before I even attempt to dig into it. Weather needs to get a little warmer...

 

tip the frame up on the back, be ready to catch nasty water that might be in the frame. then look at the frame where the side stand is welded. bang on it, make sure it's solid

 

Yeahhhh already experienced that. Frame seems solid all around, just needs to be cleaned up.

Been de-rusting parts all day

 

Krud Kutter: The Must for Rust
works great with soaking. Dump it in the frame and let it sit.

 

Dug into the swing arm and final drive. Bearings and seals look good on the swing arm, new grease and they will be good to go.

Pulled the final drive out of the swing arm and noticed a ton of metal shards at the retainer...looks to me that the PO or someone cross threaded and just tore it all up...

Removed all the shavings and turning the shaft seems very smooth, no noise or hangups. Not even sure if I would be able to remove the retainer if I tried...

Final gear oil was as expected, dirty and clumpy. Some notes of metal but not full on shavings.