82' xj750 maxim repairs.

I picked up this "new to me" 1982 xj750 off marketplace the other day, no battery, no starter and 60k km, but i bump started it in the driveway and it ran fine, and idle well also. Put it in the truck and brought it home. Besides it needing a battery and a starter.. it also didn't have the gauge cluster hooked up, rpm needle was broke, turn signals were taped on the front fork, the rear turn signals were falling off.. you know all the typical things.. seat was just sitting there...

The previous owner before me had installed the stock bars but upside down.. making the turning radius of this bike tripple id bet...

For now ive stripped the old bars, risers, ect.. off the tripple tree and thanks to a thread on here i ordered up some 1981 virago risers and ill use those for a full bar. Tanks off to get some work done to it, had a few bad dents, also took the batt box fairings off too. Did an oil change, filter change, going to go through the wiring and fix some unnecessary crimped connections, that seem to be everywhere...

Had some tail end turn signals dropped off so ive got those mocked for now. Thinking about how to close up these holes on the fender, if its worth tacking some steel in the holes or just getting a different rear fender. The risers are in the mail, bars are in the mail ect...

This is my first xj750 and my first project bike. My other build (4x4) is at a halt due to not having a garage , but the bike fits fine in my basement so thats a win! Im also very happy this forum uses the same format as my other project forum, and the how to video section is an awesome addition!


This is how i picked it up the other day, also the advertised photo.

 

Also took some photos of the starter taken apart, ive never rebuilt one but it looks like it shouldnt be too hard. Just some brushes and o rings and a crazy good cleaning might do it... Ill do some research, i think i saw a video in the how to section if i decide to tackle it myself.

 

not much of a fender on the front of it

and a big wtf on the handle bars

 

It's easy to get the starter clocked wrong upon reassembly. Do that and it will turn in the wrong direction.
Replacing your starter motor brushes w/ pics

 

i know right. the bars are ridiculous... its definitely a few peoples aborted projects in one... bars should be here next week, along with the risers.

 

i dropped it off at a shop for a quote, if its not too bad ill probably just have them do it and get a warranty. Id like to get out and ride for the rest of the season asap.

 

still havent gotten the starter quote but will shortly this week, I fixed the two big dents the P.O put in the tank so those bars to fit better upside down... and some other minor stuff with the tank. Cleaned the valve body and it all seemed good. Im no body man in anyway but it came out alot better than it was so thats all that matters to me.



All the turn signals were electrical taped on the bike and shot , replaced them with LEDs not really thinking much of it, and now im looking for a relay because my turn signals stay solid, potentially one i can ground the third prong to the bike , as ive read it keeps the auto cancelling portion alive, but ive tested mine and i dont think id trust them anyway. I read if i wanted to loose that feature i could just use a 2 prong flasher relay. The one someone suggested in that thread was a bussman 552, is that because its a good brand, or are 12v flasher relays really that different from one to the other ( serious question as i dont know much about relay specifics ).

Ordered a tail light and im sure ill have some wiring to mess with to make it work but thats just the way she goes..
Excited for time this winter to eliminate the cluster and all of that birds nest of plastic up front and free of some space, and get the harness all tucked into the frame more.

Waiting on parts still, also this factory seat is all broken, loose , and held on with hopes and dreams....Probably going to order a cheaper simple seat and just make a bracket for it, tacked to the frame for now, so i can atleast get out riding before winter comes..

how the bike sits now.

 

The Yamha system is a bit propretary, so the type of signal relay you use is really important. Grounding the third leg of the OEM relay does nothing of value, and the only way to retain the auto-cancel with LED lights is to use two relays. A two-prong relay has to be of the correct type internally or the system won't work at all, which is why the Bussman 552 is suggested (there are other relays that work, it's jut that one happens to be commonly available).

Link to the 2-relay solution.

 

I'd like to add that you could just install load resistors, but that defeats the main advantage od LED lights.

 

Thanks for the help and link. I purchased a 2 prong LED flasher relay ( with a built in resistor ) at the local store because i couldnt find a bussman552 at the parts store, I installed it, now i get one flash and then nothing. I dont have my front signals hooked up yet so im hoping that has something to do with it but they will be delivered today. Once installed later on, if they still flash once and stop, i will order the bussman 552 relay, they are only a couple bucks on rock auto and shipping isnt bad.




One of the next things on the list was a working horn, i tested power at the horns with a test light, good. tested the switch wire good, narrowed it down to the switch, once i took it out i figured itd be the problem. Simple cleaning the switch contacts and the ground solved the problem.



The clutch switch was broken in the handlebar lever slot. Switch works, but tabs are broken off... so when you pull the lever it shoots out of the housing.. I will order another one of these , but for now i just cut the wires after the connector so i dont loose it, and married them for now with heat shrink, so the bike should start while im waiting on parts like that.

 

You won't need the clutch switch unless you want to start it while in gear. It's safer to just leave it unplugged (in the headlight bucket). The new switch comes prewired, and juat plugs into the harness.

 

Installed front turn signals and got lucky with the relay. Works, has proper timing for the flash, and the auto cancel for turning left works but not right... thinking it a switch issue now. Either way, that gets one thing off the list for now.

 

That shouldn't be affected by the switch position. Without the factory relay, or the 2-relay modification, the auto cancel shouldn't work at all. It can't interrupt the non-OEM relay to make it stop flashing.

 

I got the virago risers installed, new bar installed and all the accessories that go on. in the future i will get the brake line shortened since there is quite some slack before it gets down to the prop valve. When i go the bike, turn signals didnt work nor did brake lights or running lights for the rear brake. I got the turn signals wired, front brake lever works and signals brake light, rear brake was a mess of wires and the spring on the brake switch was gone so the pedal didnt activate anything anyway. Got all that sorted but one thing that i havent figured out yet is something is going on with the brake light. When i didnt have the front brake switch plugged in , I had a rear running light, and brake light from the pedal, seemed great. Now that the front is hooked up i have no running light but front brake lever switch works and rear lever switch works but no running light.. Im gonna dive into the wiring diagram and some threads and hopefully find an answer.

I did throw some fresh fuel in the tank after the reinstall and ripped it around the block, Clutch seems good, and it runs pretty good aswell. Good enough that itll definitely get through the last couple months of riding season.

I ordered some bar end mirrors, and a brown simple seat since the stock one has all the mounts broken off of it and the frame has been no more mounting points either...
New air filter on the way to the store.
Going to order a rear brake shoe kit and replace those. Doesnt look like anyones opened it up recently...

also id like to locate a proper rear fender, this one is just bubblegum welded in there...
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The bike as it sits now.

 

Looking good!

 

Took the bike on its first real voyage the other day, put about 250 miles on in a day of riding our coastal highway. Didnt notice any major issues except the noise of the " cam chain " or whatever it may be. Ive tried to read all the forums on here about " noises " and until i open some things up, and inspect, i know i wont really know for sure what the noise is.

It started everytime and seemed to run good, didnt really push it above 7-8K rpm as im still a bit weary of the workmanship that was done before me, because i dont know much history, and it seems safer to assume towards the worst of it than the best of it.

I did loose my keys on the highway once... I found them when i went back but obviously the tumbler or something in the lock cylinder is gone because the key just comes right out as its running. I have seen some new lock cylinders online and i was wondering if anyone has relocated it. Seems like itd be easy enough? I ask because i want to eliminate the atari system hanging off my bars , and then the lock really stands out. Im not sure where the starter relay is but i imagine id possibly have to move that as well depending on location.

Its not leaking any fluids, clutch seems okay.. Im still going to take a peak inside and see if it could use some new friction plates and compression springs. Its got 60k km on it and without much history im going to assume the worst even though it does seem to have been worked on by someone quite a bit at somepoint.

The starter did click a second or two a couple times once or twice, It was just rebuilt but that doesnt mean they didnt make a mistake. Also could be electrical in terms of the solenoid and ground wire connection possibly?

One thing i was wondering is how stiff should the front brake lever be? it stops really well but its quite a bit stiffer than my other yz450f's.
rear brake pad was in good shape but i ordered a new one anyway because i dont know how old it could be..

I read somewhere about the final drive fluid being 80-90w gear oil? is that what is still best for it?

also put some exhaust wrap on it as i had a couple rolls gifted to me.. not sure if i like it or not though.

Some pictures of it now and on the trip

 

It also has a small lag in first gear when the throttle is applied, sometimes.. Im assuming its going to be something carb related so a rebuild kit and new air box boots/clamps from xj4ever will be added to the list of things to order.

 

made some progress this weekend between adulting and also putting some hours into the new E150 campervan. Got the carbs off the bike, once i started looking at them closely i couldnt stand it anymore, plus i had the tank off because my petcock was leaking anyway.. so the MAW ( might-as-well ) set in and off they came. Rebuild kit should be here this week sometime, so i figured id get some prep work done. Got the " freshly cleaned, haha " carbs off the bike.





They were clearly very gunked up. Not done cleaning by all means but threw in the towel for today. I have all the jets soaking in carb cleaner in the float bowls. Nothing seems scored or junked but the gaskets, someone also threw in an oddball needle valve. I will be replacing them all with the rebuild kit i purchased anyway, as well as the main jets but ill clean and save the old ones.

 

Those are not too bad at all, but don't let that fool ya, those emulation tubes could be nasty. Make sure you get that little jet in the bowl all cleaned out. Bred tie works well with compressed air. Great pics keep it up!

 

Yea they aren't as bad as some of the videos I've watched that's for sure, so that's a good thing. I did blow air through them and carb cleaner so far. Also wondering what kinda material I can use to get the discoloration off the diaphragm bodies or if it's fine to have that color on them?

As for the emulation tubes. Im going to take some wire off my wire brush, and go through every hole before assembling again.

 

All of the jets are the correct size except for the pilot AIR jets, which should be the #205 for Canadian XJ750 carbies……..the #195 size is for XJ650 engines:


HITACHI PILOT AIR JETS:

The pilot air jets on all Hitachi HSCxx series carbs are located under the vacuum piston diaphram, and are a small, brass "headless" screw-in jet. On some model carbs, these air jets live under a small, curved "cover plate" which is retained by a special shouldered screw (most later-model Hitachi carbs seem to have dispensed with this air jet cover plate, although its threaded mounting hole still remains in the carb body).

Replacement Hitachi pilot air jets are now available for these model carbs, in both their original sizes and in optional "tuning" sizes for use with pod filters or other special tuning purposes.


#195: all 1980-81 all XJ650 North American models, all 1982 XJ650RJ and RJC Seca, all 1980-82 XJ650 UK/European (4K0 and 4K1) models, and all XJ650 Police (37G) and XJ750 Police (24L and 37H) models.

#205: all 1982-84 XJ650 Maxim North American models, 1982-84 XJ650 UK/European (11N) models, 1981-83 XJ750 Canadian models, and 1981-84 XJ750 UK/European (11M) models.

 

bread ties = bred tie

 

Careful. We don't want any baby ties running around underfoot.

 

Thanks for that! the kit i ordered is from the US so i dont think they are included but i will order some proper air jets

as long as its not family bred, its okay i think.


I also found some boots locally, which was a huge shot in the dark. The new vs old.

 

been working crazy hours with all the tower cranes having to come down right now at work but i have had parts showing up. Found some brand new brake pads on craigslist, got the carb rebuild kit finally, fork seals since i definitely tried to fill them up at the gas station and blew them up.... oh well, by the color of the fork oil they are in a dire need to be changed anyway. I ordered a 4 prong fuse box to replace the rats nest the previous owner made. Its soldered atleast but its just sloppy n gross looking. The fuse box may be a bit too tall, so im going to see where i can maybe place it, or if it'll fit under the seat..

For now i just tackled getting the carbs finished and installed, new boots in, new inline filter and hoses installed, tank back on and a test fire. She fired up nice and seems to run a lot more smooth. I havent gotten it outside yet to re adjust the idle mixture or whatever but she seems happy for like 5-10 seconds she ran in the basement. heres some pics i got. some might be sideways..

 

Only parts i had to change in the carbs was the needle valves and the screened jet? nut looking part that the fuel flows through, and the #43 jets since i had one i was suspect about. Other then that everything seemed fine and just needed a good cleaning.... also got impatient and re-assembled before the parts i could change for the sake of it arrived.

 

oh and heres the ratsnest..tinder..BOMB.. or whatever ya wanna call it haha..

 

Eeeeeeewwwww

 

haha yea its a damn mess for suuuure

 

Throttle shaft seals checked out OK? Supple?

 

Im not entirely sure what you mean by throttle shaft seals, I dont know the technical aspects of carbs very well yet, first time ever cleaning one.


EDIT: just watched some videos to fin d out what you meant, and to be honest i didnt get that far into them this time. This bike will be getting a lot of work over the winter, including engine tear down and what not. I thought i could get away with just a decent good cleaning of them for the last 2 months until i get 6 months to work on this thing in the basement. The linkage and all the shafts seemed fine, and didnt damage them while cleaning.

 

Plan on doing them this winter.
Why you should replace butterfly (throttle shaft) seals.


Why the engine teardown? If internal work needs to be done then there's no reason to make her run until that's been completed.

 

I will for sure go through the rest of the carbs this winter, and I have all the parts from the full rebuild kit already on hand ( although I may need some more parts for the throttle shafts)

I have no reason to believe the motor needs to be torn down at all. Runs good, but just has 62k km on it and with what I can see on the top of the piston through the spark plug hole, I can tell it could use a good cleaning and once over most likely. I don't think I'll need to rebuild anything ,but a good fresh set of seals, a solid clean, and maybe a cam chain or something at 62k km is probably a good idea I'd think?

 

Also thanks for that write up. At a glance looks very helpfull. Will give a full read later.

 

At 62,000 KM the engine is barely through 1/4 of its expected life before needing a major service. Leave her insides alone for now. Teardown and reassembly is a big chore, and a lot can go wrong in the process.

 

whoa okay, thanks for the knowledge. I didnt think these motors would have such a long life. I will definitely focus on other aspects of the bike then.

 

Today i was at the bike salvage yard by my house just basking in the new glory of heaven that this place is.. and stumbled upon this gauge cluster in the drawer of yamaha clusters. Mine has none of the warning systems still connected and i dont really plan on going through fixing it and i really like this style cluster. It had 81 xs1100 written on it but from a google search it seems a bit different but im not sure, currently trying to find a wiring diagram for it so i can identify each wire and wire it into my current harness.

I spent a bit of time going through my harness today identifying everything i need and making sure i dont cut anything i need out, still got more to do but this cluster doesnt require much. Turn signals, tach, speedo (mech.), power for lights, neutral light and high beam. It will require me to wire in the connector for my headlight ( since the OE one comes out from the cluster ) which i plan to cut from the cluster and use. With the wiring diagram im sure i can find a suitable power source, and i have an empty ground connector from the old aux lamp i can use to ground it. Ill have to figure out how the high beam switch is wired in so that works as well ( thank god for the haynes wiring diagrams ! ) Wont be quick but i think itll be a big upgrade to the look im going for.

 

Not sure why they upload sideways.. they aren't sideways on my computer or phone..

 

Also it appears the cluster is from a 79 xs1100 not a 81

 

There's more to do if you want it to start up with your new cluster.

Here's the wiring mods to remove the rectangular instruments
The writeup is for the Seca, but the Maxim wiring is similar.

 

So I can't find a wiring diagram that matches all that well and decided to just open it up and chase the wires. I've got them all labeled except these two that go into where the odometer is. The black plastic piece is not coming out and don't want to break it. Would these be just more lights?

 

At this rate I'm gonna owe ya some beers for saving my butt!

 

That is a reed switch that is used to provide pulses to the auto cancel unit for the turn signal flashers. You will need to wire that up if you want to keep the auto cancel function.

 

Thanks! Seeing as I had to eliminate that function when I went ahead and bought LEDs not knowing any better, it'll be one less thing to wire in.

 

there a wiring diagram that allows you to keep the cancelling function with led lights.

 

That was brought to my attention before but the auto cancel gone doesn't bother me.

 

So I have everything wired up and it's all working good except for the tach sits near zero at idle but moves smoothly upward with throttle. I'm assuming low voltage at idle is causing this problem even though my old tach read fine. I'm probably right in assuming it's from me re wiring this, but any shot in the dark ideas out there? I've checked the connections and with the motor off/key on I'm getting 11.58v at the tach connection in the headlight bucket. And the same while running at idle.

 

Edit: I am now getting 13.5v with the black ground and grey wire to the tach, and 12.58 with ground on the black and positive on the brown wire but the voltage stays around 12.58 then goes down to 6 for a split second and then back up to 12.58 ish.. I sure done opened a can of worms now haha.

 

My diagram shows the grey wire going to the tci unit and the coil, and the brown wire to the signal 10a fuse

 

could be the coil is misfiring for some reason or bad connection at the connector.