XJ550 (re)build

The old saying goes "be careful what you wish for, it might come true" ... Well, I wished for an oldtimer to wrench on.

So, I bought an XJ550, basically on a impulse, because it was old and looked really cool (yeah, I'm stupid like that). Bike started right up so no worries, right?



Well, apparently the PO was more interested in a quick turnaround than doing things properly. "A fool and his money ..." is another saying. I'll try and document my (re)build here for your amusement and education.

 

Problem #1: The bike doesn't always start, and stalls or stops when idling or downshifting.

I outsourced this problem to a local mechanic that works on old bikes. He did a complete carb rebuild and fixed some other minor stuff. The stalling/stopping issue seemed solved, but the bike still didn't want to start when cold or standing for a couple of day. In the meantime, I found these forums and learned that my battery is probably the issue. I checked and it started fine on a fresh charge, but wouldn't when standing for a couple of days. Measuring with a multimeter confirmed that the starting charge was weak. So, a new battery was in order! Which led to ...

Problem #2: The wiring seems to be an incredible mess!

I finally managed to remove my saddle to get the old battery out and was greeted with a rats nest of wires. I know I'm new at this stuff but this doesn't look like a solid wiring job at all!





And why leave (not) well enough alone? Let's put a Motogadget m.unit blue in there (with m.button and m.switches mini), and the starter solenoid and inverter/rectifier from Revival Cycles. Yeah, that makes total sense.

I was starting to doubt the PO's skills at this point, so maybe I needed to looking into some some other stuff. Like the engine!

Problem #3: check the valves!

When researching the forums, valve clearances are mentioned often. I better check those, then. The tutorials seems straightforward enough, so I should be able to do that - I hope. So, let's get that tank off so I can reach the wiring and engine. Oh-oh ...

Problem #4: the tank is in a sorry condition.

Since some of the paint on the tank started getting bubbly, I knew there were some issues with it. After draining it and taking it off, I got a better look. The inside is splotchy and rusty. I'll need to treat it and see if it can be fixed or if it has to be replaced.

Buy a bike, they said. It'll be fun, they said.

 

I started stripping the wiring from the bike, today. The idea was to start taking stuff off (lights, turn signals, ignition ...) and see if I could make any sense of the madness that is the current wiring. Here's some of the stuff I found:

duct tape is apparently a substitute if you run out of electrical tape:



I'm not an electrician but this seems a shoddy job to me:



Are wires supposed to be stripped over the complete lenght?



I also found any number of wires not connected to anything, a gazillion different kind of connectors and about 20 kgs of tape. So, I stripped everything. Much better now!



In the coming days I'll try and lay out the main components from the old harness again to make more sense of them, and start a rough POC of the new one on a table with the m.unit. If I manage that, I'll be happy.

 

very wise to replace that harness.

 

I gutted some mystery components from the wiring harness. Maybe someone can help me identify them?

I think this is the starter relay/solonoid, yes?



No idea what this is.





Or this.



Or this?



Or this little plastic square?



Any help would be tremendously appreciated.

 

See my replies in red within your quoted post.

 

Thank you! I'm replacing the starter solenoid with a new one (https://shop.revivalcycles.com/universal-starter-solenoid-with-main-fuse/), the turn signals will be managed by the the m.unit. Looks like I don't have to worry about those, then.

I was looking at the factory wiring diagram a lit bit earlier AAMOF and was wondering about the diode block. Being a complete noob, I threw "What does the diode block do bike" query in google and lo and behold, this forum was in the top results! https://xjbikes.com/forums/threads/whats-this-wire-and-what-does-the-diode-block-do.113629/ I'm not planning on restoring the factory wiring (m.unit) and it's not mentioned on the minimal wiring diagram for an XJ. Does this mean I can do without? I also remember another discussion on this forums on how to adjust the minimal wiring diagram to integrate the side stand safety without using diodes (also for an m.unit integration), I'll have to look that one up, then.

Fake edit: the m.unit blue has a built-in kickstand and clutch switch. So, I won't need the diode, apparently.

 

diode block controls oil level sender and oil light test when starter button is pressed this feture is important
.


another is the headlight relay diode
side stand relay uses a diode for grounding through clutch switch and neutral switch .
the factory service manual for the 550 shows the diodes in the wiring circuits as individual diodes not to be confused with the internal diodes in the headlight and starter safety relay.

 

Thank you for that information, XJ550H, you're a lifesaver! Good thing I saved it from the harness, then.

 

So, as per advice of this forum, I measured the resistance of my charging system - albeit belatedly. I measured resistance between each of the three wires coming from the stator, and no resistance between each of the wires. According to YT, this is as it should be.

I also removed my exhausts, since I noticed on a vid of my bike running that I appeared to have an exhaust leak. As with everything on the bike, it wasn't hard to unbolt them. I hardly even needed tools! Two of the bolts probably broke off, as they have been replaced with tapped holes and bolts (in a different size than the other bolts, because why not). After comparing my exhaust rings to the ones in the DIY thread, the cause for my exhaust leak isn't hard to find. So, I definitely need to get some new ones!



I think I can see where the leak is based on the soot on the pipe.



The ports could use a little TLC, too.





While I'm waiting for stuff to arrive - so much stuff - I started mucking around with the m.unit. I made a little CAD (cardboard aided design) to see where and how I can fit everything on the bike. Luckily I have some guys at work that can help me fabricate it in steel. The battery (strapped down) and m.unit would sit in a tray, the starter solenoid is mounted on a bracket above and the inverter/rectifier is would sit on the outside of the tray. That leaves with some free mounting space for fuses, a couple of battery charging pins and other stuff. I also plan to mount some hinges for the saddle so I have easy access.



Those metal strips are used to bolt down the custom sidecovers, but they're completely booger-welded and the more I see that, the more I hate it! They need to go asap, but not completely clear yet on how to best go about that. Tough place to get a grinder in.





Somewhat finalized design. Please tell me if I forgot something or if I'm just being stupid.

 

You really ought to figure a way to incorporate an airbox of a similar volume to the stock airbox. The mid-RPM bog that comes from running pods can't really be gotten rid of (it can be made almost nonexistent with a good amount of time and money though).

 

The open pods were on the bike when I bought it, and it's only after reading this forum that I learned the XJ's don't like that setup. I'll have to see where I can get one, though that'll be a worry for when I finish up all the other things I have going on this bike.

 

may want to consider some thread repair for the bolts in the header pipes. for the gaskets the copper oem style seem to work better than the aluminium ones. had to keep retightening the nuts several times to get the full seat of the headers when I used the aluminim ones. copper just 1 retorque.

could just be me or the style of exhaust I used mac 4 to 1 was the one with problems the hold downs is welded to the pipes unlike oem exhaust.

check this link out page 9 for battery location
https://www.xjbikes.com/forums/threads/stebers-81-xj550-bobber.98704/page-11#post-612876

 

Thanks! I hadn't considered that approach; it would give me a lot more real estate to work with. Back to the drawing board.

 

Man, electrical work is terrifying.

 

think like a plumber.

 

the builds not over until you sell the bike
there is another thread on a build where the member made a battery box and components holder where the air box once was

 

Man, plumbing is terrifying!

 

yup that's why I stick to electrical work

 

I get that you ddn't do the work to remove the airbox. There are a few threads here where members built airboxes that fit into the same space that the pods do, but work nearly as well (or even as well) as the factory airbox.

custom airbox site:xjbikes.com

Bensalf's is particularly interesting, and may be a good fit for your situation.
#64

This M Unit thread might be useful to you as well.
relays-or-not-to-relay.72383

 

Thank you! I've been reading up on pod versus airbox discussion on the forums here, and it seems an airbox is the way to go. Unfortunately, I can't seem to find one anywhere! What I'm currently thinking is some kind of bread box (a new term I learned today) based on the this part of the original design:



So, using parts 1-2-3-4-6-7-9 coming from the carbs, fabbing a plate onto that to house them and the filter and have it feed from the left side if possible. Does that seem like crazy talk? It would at least be better than pods by restricting the air flow, right? My biggest problem right now is that I don't have an original to examine and measure to use a guide (and steal while the owner isn't looking).

 

crazy talk? you are looking at the front manifold to carb boots with those part numbers , parts 1-2-3-4-6-7-9
7 and 9 are carb to airbox boots and clamps.

 

Well, you never guess what I found at a wreckers in the next country over ... Now I just hope they got the model right.

 

Today, using the technique from the video XJ550H kindly provided, I cleaned up the airbox I got from the wreckers. My bike might not be running atm, but it has got the smoothest airbox now! Took my a couple of hours (and a lot of elbow grease) but it cleaned up nicely. It's colour faded now, however, so I'll have to see to paint it. Also, I'll have to patch a hole where the filter panel is, a piece of the housing was cracked off. I'll have to look at some of the seams, too. Still, the boots some in decent shape.

 

Just checked what it would cost to get all new boots, clamps, gaskets, joints etc. for my airbox and it came to almost €460.

 

Ouch, that is pricy. I have not looked into replacing those. I did like your idea of shortening the box

 

How much is a new bike in comparison?

 

Yeah, I know. And I'll get the new parts in the end, because that's one less thing to worry about. I just assumed it'd be cheaper. Oh well ...

 

The PO replaced the side panels with custom ones. Looks cool, only he half-assed the job like he did everything else on this bike. They were also limiting the available space for reinstalling the factory airbox and the electrical system. The boogerwelds were really rustling my jimmies, too.

Before:


After:


I also removed the carbs (they were already cleaned and sync'd by a mecanic so I won't touch them - for the time-being). I don't think I'll need to replace the intake boots.

 

That fella sure did use a lot of metal just to hold some sidepanels on.
Had he never seen tabs before?

 

You can always try the 'boil in Wintergreeen' trick to make the rubber parts supple - works for a few weeks at least.

 

Ordered a complete engine rebuild kit from Chacal. It's due to arrive in the coming week(s), so I can get started on tearing it down first. Pretty scary since I'm a total noob at this stuff but the Haynes manual (supplemented with Google/Youtube) is providing me with a plan!

Removed the carbs, clutch assembly, stator, alternator and got started on the top of the engine.



This just look nasty!:



These sparkplugs have about 300 kilometers on them (185 freedom units). The ones from cylinder 2 & 3 were also darker than the ones from 1 & 4.




The good work will continue tomorow (hopefully).

 

Please, please, please stay away from Youtube for anything but general help (and be cautious even then). Very little of what is on there is accurate, pertinent, and XJ specific. I don't have enough body parts to cound the number of times we've had to help unfix something somebody learned how to "fix" from a Youtube video.


The stator is supposed to look like that. The Laquer used on the windings isn't meant to be pretty. It's there for functiom. DO NOT clean it off.
Any oil can be cleaned off with electric motor cleaner (not contact cleaner).


The plugs are all a bit rich, but not horribly so.

 

That's solid advice, imo. I don't use YT as my go-to help channel for my bike (I have this forum and my Clymer for that) and when I do, I try to be critical of what they're saying. But sometimes it's handy, like how to get a clutch assembly without a clutch removal tool (I used a leash to wind around it to give friction).

Good to know, thank you!

 

Save one steel and one friction plate.
Drill two holes in each plate 180º apart. Drill a flat steel bar to the same spacing. Bolt them all together.
You now have one, nearly free, clutch basket tool


[EDIT] the hole spacing is not 180º. you need the bar to be offest from the center of the clutch plates to provide clearance to undo the center nut.

borrowed pic to show the bar placement. the tool is missing a plate.

 

Too funny!

 

Remind me again why you are looking to rebuild the motor. Has it done inter-galactic miles? lousy compression readings??

 

At least 65000 kilometers (+- 40000 miles) - that I know of. The gauge with the odometer wasn't stock so your guess is as good as mine. ¯\_(ツ)_/¯

Couple of reasons:
- I need to check valve lash, so I needed to open the engine anyway.
- The bike suffers from POS (= previous owner syndrome) so I want to be sure everything is okay. Something worth doing is something worth doing well.
- Part of the reason of buying an old bike was wanting to learn to wrench on them. Mission accomplished so far.

 

At that mileage I wouldn't be bothering unless it shows signs of needing it, low compression, using oil etc, they easily do 2 or 3 times that without needing rebuilds unless it's been subject to serious abuse

 

For the valve clearance (lash) you only need to take off the rocker cover (your top picture) obnvce that is done I would check compression. If all ok then 'job's a good un' .
I'm all for a bit of learning but taking apart a good engine could prove folly. Even if you do find something slightly out of spec, say worn bores. Do you really want to fork out 500+ Euros for a rebore, assuming you can even find oversized pistons? For learning buy a ratty chinko 125 (CG125 wannabe) cheap parts and no big deal if you screw something up.

BTW form what I have seen it loks like the PO only messed about with the cosmetics and electrics. By all means fix that first and if the engine later proves to be trouble then you can start stripping down if yu think that's economical to do.

 

+1 I have a 650 in the garage with 44k miles on it and as soon as I find a suitable titled frame for it, or get a title for it's current frame, I fully expect it to run and shift just fine for as long as I want it to

 

Thank you for the feedback, you raise a few good points. Leave well enough alone, and all that ... A rebore would def. not be in the works. So, I've ordered a compressiontest set and see what that gives.

 

(stock) Fuel tank arrived today and it looks awesome on the bike! So much better than the aftermarket one that was one there ... It'll also hold more fuel, so that's another plus. All in all, it's in decent condition. A small dent and some scratches but fixable. The inside was rusted, though. I had already ordered a POR15 fuel tank kit and today was a holiday, so I dove straight into that!

The kit holds a tank cleaner, rust remover, a sealant and some fixing gauze if you have small leaks (none, so far). A whole of shaking, waiting, rinsing, shaking, some more rinsing and drying (paint stripper gun) later, I'm ready to seal it. I'll give it two more days to dry completely (busy tomorrow) before I do that. I'll also strip and primer the outside then.

 

So, I sealed the tank today. Pretty happy with the results! All the rust's gone and it looks nice and shiny on the inside now.

Before:


After:



Once I get some body filler, I can start on the outside.

I finally got the heads off, too. Looks like I have a lot of cleaning up to do.

 

Yesterday, I stripped the paint from the outside of my fuel tank. I used a chemical that you just slop on, let it do it's thing and you can scrape the paint off in 20 minutes. Well, it worked as promised but it took longer than 20 minutes. I've learned it always takes longer when working on bikes. Judging by the body filler I uncovered, this tank has already been places in its life. Also, after rinsing the stripper off, it started rusting straight away. So, I gave it a quick sanding and applied some anti-rust. After letting it dry for a couple of hours, I gave the tank a coat of black primer. And decided to have it painted rather than doing that myself. ;-)

 

Today I started cleaning the head. I took the valves out with my shiny new valve spring compression tool and started scrubbing that built-up carbon out! And look what was hiding beneath all that grime ...



Wait, what's that on the number 2?





Let's check the piston!






How f***ed am I on a scale ranging from "She'll be right, mate" to "You're turbo-f***ed"?

 

You're fine. The damage is minimal. Clean it up and run the parts. Heck, it's clearly been running that way for a long while already.

 

Good to hear! ^-^ I wasn't looking forward to having to find a new (old) block.

 

something got in there - but it's not there now. How was compression on that one?

 

By the time the compression set arrived, I'd already taken the head off. =/ Not my brightest moment, in retrospect.