1981 XJ550 4U8 Refurbishment

Good morning,

I became a member a little while ago when searching for info on my old 1981 XJ550.
It had been stored behing my garage under a tarp for the last 30 years! I bought the bike in 1986.
I had always planned to restore the bike but as usual...life just got in the way...

A couple of years ago I descided to "bite the bullet" and drag it from the graveyard... It was far worse than I ever imagined and for a moment contenplated scrapping the bike....

I'm pleased to say though that I didn't and began the long process or restoration...a very long restoration.
I have found this site invaluable to the work I have carried out so far and give huge thanks to the site and all those contributing. I thought it only fair that I give something back that may help others or at very least let people see what kind of transformation and satisfaction you can get from this kind of project.


I am still quite a way to getting the finished article I am looking for but as time allows will post each area I tackled to reach where I am for those that are interested.
Thanks to a great site full of invaluable information!

 

Good for you. Spectacular before and after photos. So nice to see one brought back from the brink of scrap. Thank you for sharing.

 

Super restoration.

 

OK, I am not sure if this is the correct place to post my route to getting to where I am but as this is simply my story so far … please let me know if it needs posting somewhere else.

I started the project with a really good washdown and jetwash with everything still attached to the bike. There was plenty of cobwebs and general “crud” covering the whole bike as you can see from the first images. Both the ally and steel corrosion were extensive….really extensive….

First thing was to see if the bike turned over. Removing the side cover and gently rocking the nut on the pickup points showed the bike had seized solid…not really a surprise!

I removed the plugs and filled each hole with a good amount of carb cleaner, left it for 24hrs then tried rocking the nut again – Nothing. I repeated the process over the next couple of days adding some 3-1 oil to the mix. After 3 days the bike did shift and the pistons began to move for the first time in many years – probably 25 years since it was last struck up!

Once the pistons were free, I poured a good amount of engine oil in each cylinder and moved onto my first job..

 

I decided to refurb the carbs first. In my youth I though it a good idea to spray the carb bodies black with a gold top and bowl – like a Duracell battery. Don’t ask me why….crazy things you do when you are young!!


All linkages were seized, and the tops quite corroded with little chrome left. The slides did still move.

I stripped them completely carefully removing the gunk with carb cleaner, and toothbrush and pipe cleaners. I used a rotary tool with small scotch type pads and soft wire brushes to polish each part. Care was taken to clean out all holes using tooth picks.

On removing one of the jets I broke off one of the float pillars… I should have used a socket with extension bar but didn’t…. Using a standard spanner was bad news.

After much reading and referral to this site too, I used JB Weld to glue the pillar back on. It appeared to work fine and was quite solid. I then tested the fix overnight by soaking the part in petrol to see if the fix would hold – It did. It was the No.2 card body.

I’m sure the repair would have held but a nagging doubt was there so I purchased a used carb body from Ebay. On arrival I found that the body was from a No.1 carb so the petrol feed was only on 1 side. After careful measurement I decided to drill out the blank port on my pillar drill to allow the repositioning of the carb. With care, this worked fine and I had now created a replacement.

One of the float bowl drain screws was seized solid so I did try to drill this out. I failed miserably and had to buy another from Ebay. The replacement had no drain screw and I could not find them anywhere. I decided to make one. I found a bolt with the same thread and turned down both ends the match the original screws. I then put a simple slot in for a flat screwdriver, tested the part for a good seal leaving the bowl full of petrol over night – success!

I bought a service kit for the carbs and replaced all of the rubber seals along with the small flared shaft seals that sit each side of each carb on the butterfly shaft – these are very expensive!!!!

As the carb tops were badly corroded I decided to paint them with a chrome finish paint. It looked OK as per the images but not quite as I wanted. Also the steel parts that had been cleaned and polished would soon corrode as the factory protection was long gone.

After much research I decided to try my hand at nickel plating….

I bought the required solution and run a few test parts – they came out OK! I then stripped the paint from the carb tops and plated them and all other plain steel parts.

As there was extensive corrosion on quite a few of the parts (mostly the linkage rods and the carb tops) the finish was never going to be perfect but they turned out OK. I think better than paint and I could not think of any other way to protect the steel on the linking rods/levers.

Overall very far from perfect but I was pleased with the transformation and everything seemed to work as it should.

The only thing I may have to address is the first owner had drilled out the air intake ports, threaded and fitted jets. This was due to the “pods” fitted. Although “Pods” is not the right description! They were more like a piece of can with a fine mesh on the end – no real filter at all!

I was told when I bought the bike that it had been fitted with high lift cams, 4 into 1 exhaust and these home made “pods”. In fairness it did run fantastic and pulled really well without missing a beat. I’ll leave “as is” for now and see how she runs later.

 

The images posted are before the nickel plating.
I did reuse all of the original jets and needle settings as the bike was setup and ran great. If I have issue this may need to be reviewed.

 

The next thing I tackled was the fuel tank. This had been stored with whatever fuel I had left at the time so had more holes in it than a Swiss Cheese!

I had trouble finding a 4v8/Seca style tank (there were plenty of Maxim tanks) so decided to get the original acid dipped with a view to getting it welded. I sent it away for dipping but what came back would have taken a lot of cutting and welding…

Eventually I did find a tank for sale overseas at a reasonable price. It had a good layer of rust inside but looked fairly sound. I initially filled the tank with Evaporust and left it for a month. This stuff works great! I rinsed the tank and repeated the process to get the final few bits of rust.

Now with a rust free tank, I had a dilemma… I will not be using the bike regularly and there will be times when it will sit for long periods. Leaving the tank full or empty may not always happen… Should I line the tank?

I have read so many mixed thoughts on this and wondered for a long time before deciding to line it using POR15. The process was fairly simple and I had plenty of time to allow the solution to cure.

Time will tell if the decision was the right one….

I did also find a set of original decals, I thought these would be almost impossible to find so bought them. A story to tell here later….

 

My original tank, I lined with POR15. It held up well, but I ended up finding a NOS tank that I've left bare and will use fogging oil over the winter. My old tank is very serviceable and with new paint would look the part (in case you need another option).

 

Thanks for the offer....hoping not to need it but always good to have another option..

 

The next job was the frame.

This had corroded so bad that a gaping hole had appeared on the lower engine mount bracket on the left. The bike had been sat on the side stand so all water/moisture damage was all down the left hand side.

I did look at replacing the frame but again the only ones I could find were Maxim frames. I guess these are probably the same but I was not sure. Also, I would have the dilemma of the frame/chassis number – ideally, I would have liked to keep this original.

I decided to have a go at repair. As the rotten section was on the engine mounting point (bracket had completely rotted away) I needed to tack the repair in situ with the engine in place to ensure the bolts would all line up. So this was the time to do it before removing the engine.

I cut the remains of the engine mount bolts off and cut away all the rot/rust. I ground back to good metal making the hole as square as possible to aid with patching up. I measured the frame and bought a good thick piece of tube the same external diameter. The tube was far thicker than the original and thicker than needed, 4mm – but this would give me more thread for the bracket bolt and make it easier to weld. I cut the required size piece and offered it up – looked good. I then decided to get a flat 6mm plate and weld that to the half piece of tube to ensure a nice strong and longer threaded section for the engine bracket.

I then took some 10mm bar, cut to length and threaded both ends to replace the engine mounting bolt. Bought some new engine mounting brackets from Ebay and clamped everything in position. Drilling and threading the new piece I then tacked it in place.

There were a couple of other spots that needed to be welded and one more “patch” required but the rest of the frame appeared sound.

I did think about getting the frame dipped and powder coated but needed to keep the cost down to a reasonable level so stripped and sprayed instead. 2 coats of primer, 2 coats of undercoat and 3 top coats – I used a satin black top coat.

The finished job looked OK. Some pitting in places but structurally sound.

 

For the eagle eyed readers, I forgot to add that the patch was fully welded once the engine was out and the frame stripped - not just tacked.

 

Wow. I've never seen a frame rusted that bad. You sure it wasn't parked underwater?

 

Neither had I.... That's what 25 years of great British weather (and bad neglect) does ...
A tarp is no real protection.... All self inflicted I'm afraid. Made hard work for myself

 

The forks were the next thing to tackle.

The pitting on the chrome was extensive. Initially looked for a complete assembly for replacement but nothing available. Again, plenty of Maxim fork sets but these only have 1 brake calliper so the lower leg casting would be missing a set of fixings for the second calliper. I would have to strip and either replace the stanchions or have them ground and re-chromed.

After removing the securing circlip from the top of the fork, the end cap should “pop up”…. Not a chance! I tried everything to get the cap to move – Soaking for a week in oil, Evaporust, boiling water…nothing worked. I would need to somehow pull the cap out of the fork stanchion. In the end, I drilled a hole and threaded the “cap” – The idea was to insert a bolt with a large plate and tighten up pulling as it went. This seemed a bit drastic as I would then need to weld up the cap later for reuse but could not think of another way..

It all went fairly well and the bolt did soon pull the cap out – success!

Stripped and cleaned all parts. Fork grinding and re-chroming is expensive so I began looking for replacement stanchions. I did buy and try a set from a Maxim but these are 36mm diameter and mine were 35mm….

I eventually found a set from China (Ali Express). I was not sure how good these would be as I had heard some horror stories but they arrived and looked quite good. I’m sure the chrome is probably not as thick or well done as the original but worth a try. The only thing I was a little disappointed with was the end cap arrangement was very different. They were made with an adjustable cap (see images) not the standard fixed circlip fixing. I suppose technically this was better as the forks would have some adjustment for ride. They fitted a treat and looked quite good at a very reasonable price. At least I would not need to repair that end cap!

I put the original parts safely away in case, at a later date, I wanted to get them ground and re-chromed to put the bike back to more original.

 

I was now in a position to strip the rest of the parts from the frame including the engine. Wheels were stripped of all old paint then repainted the original black and fitted with new Avon tyres. There was a lot of work to get the rims back to polished aluminium - New wheel bearings installed.

Front disks stripped and repainted. New shoes on the rear. Bars, fork yolks and all ancillary parts were stripped and repainted. Switch gear all stripped cleaned and switch housings painted with new stickers applied.

The lower pipes on the oil cooler were rotten through but the cooler radiator looked OK. I did try to remove the pipes from the cooler but these were stuck solid. Even when cutting through the large nut holding them on, they would not come off! – looked like some kind of liquid weld had been used! I did end up destroying the cooler trying to remove the pipes…. Another thing to find and replace!!

It did take some time to find a decent replacement cooler (over a year) but after several failed attempts I did get one. For some reason the lower rigid pipes were longer than the original so they sat a little differently but when installed all worked OK. I did leave the lower engine casting attached (the bit under the oil filter housing) from the replacement as I did not want to damage the pipes as I had done previously…

I cleaned up the externals of the engine and repainted. I thought that I would more than likely need at very least a top end rebuild but for now just wanted a clean engine as a starting point to put back in the frame and test. I suppose I could have rebuilt while it was out of the frame but was curious if it would fire and run.

I stripped and rebuilt the starter motor. I had to drill out and install a Hellicoil as 1 of the starter motor mounting bolts had sheared (This was left by the previous owner years ago).

Footrests & brackets all stripped and repainted. I nickel plated the rear footrest plates & Fixings. New footrest rubbers all round. Replacement centre stand.

The wiring harness wasn’t too bad but did need a few connectors replacing.

The 4 into one exhaust was shot…. completely rotten. I bought a set of original downpipes and collector box in nice condition. I thought I would like to go back to 2 pipes out the back instead of one. This will probably mess with the jetting but we will see….

I also picked us a cheap set of shocks, not the best but in good condition and sort of resemble the original style/type.

I was now in a position to put it all together bolt the engine back in and see if she will fire up…

 

Bought a new battery and was ready for my first test run..

Put the kill switch to the centre, pressed the starter button and … nothing! I was more than a little disappointed. I traced the wiring back and everything seemed to be connected correctly.

To test if the starter was receiving power I put a direct feed from the battery to the starter motor – This turned the engine over just fine, so the issue must be further up the wiring harness. After much head scratching and checking with a Multi-meter, I discovered that the starter button needed to “ground” when it was pressed. When I checked continuity from the switch housing to the frame there was none. I discovered that when I had painted the bars and fork yolk, the paint had formed an electrical barrier so no earth was connecting when the start button was pressed. To get around this, I ran an earth cable from the fixing screw inside the switch through the loom and back to the frame. This worked a treat and the engine turned over when the button was pressed.

I bought a cheap test fuel tank – One of the drinks can sized units so I could run tests without putting fuel in the tank as I still had work to do with that.

A squirt of “Easy start” in each cylinder and … Wow, she fired spluttered and then stopped… It was quite exciting that some life came from the engine after 25/30 years! A bit more “Easy start” and try again.. It did take quite a bit of turning over to fire but then the engine ran! A bit of popping and spluttering at first but soon smoothed out and after 10 mins ticked over just fine, quite noisy as no silencers were fitted at that point.

I did notice that there was quite a bit of what appeared to be smoke maybe vapour from the breather… After reading a post here, decided it could well be vapour after so many years of sitting.. I ran the bike for 20 minutes until hot but the smoke/vapour did not appear to be stopping.. It was then that I remembered 35 years ago, when I was riding the bike daily, it did smoke from the breather. The previous owner had fitted these “Pods” as described before and had simply ran the engine breather into a plastic bottle with holes at the top strapped to the frame where the airbox used to fit. I remember smoke/vapour used to stream up from under the seat!

I assume this was more than likely “blow-by” or valve stem seals… The Vapour/smoke is quite white though ... not what I would describe as blue in any way. But there is quite a constant stream of it. Although my memory is a bit vague from all those years ago, the bike never burnt any oil.

I will finish the rebuild then move onto a top end rebuild when I get the chance. I did pick up at this point a spare set of barrels with pistons, and from a separate source, a spare complete cylinder head. My plan was to refurbish these first then simply swap them over.

If the bike was/is fitted with high lift cams, do you think I should go back to original cams by refurbishing the newly purchased head and fitting that or strip out and refit the high lift ones - What do you think?

 

I moved onto the mudguards next. The front mudguard was never original, it was plastic with a monster, home-made fork brace. I ditched this along with the home-made brace and looked for an original. I had always intended on spraying it black – not the original chrome.

Once again, there were plenty of Maxim mud guards out there, but I could not find any decent ones for the 4U8 models (Seca ones are the same too). After reading somewhere here, I did see that the XJ650 had the same front mudguard – I found an XJ650 one (painted blue) in good condition. A simple respray and it fitted and looked great!

The rear mudguard was always missing from my bike. The previous owner had removed it and screwed a crude steel plate under the seat. They made a simple bracket bolted on the rear of the frame to hold the tail light (a Suzuki light was fitted) which sat further into the tail piece. I believe it actually looked better than the original, I was never over keen on the right angle of the plastic guard and always thought that the tail-light stuck out too far but that is only my opinion. The makeshift plate under the seat gave no real protection from the wet and did not form a full mudguard. I contemplated making a rear mudguard but didn’t really have the tools, or the skills, to do a good job.

I then looked at the Maxim rear mud guard. I thought this would sit nicely in my frame and do the job I wanted. Unfortunately, the mudguard was very slightly too wide to “marry up” with my mounting holes at the top so I made a couple of short steel brackets to mount it. This pushed the back of the mudguard down a couple of inches but worked to my favour as the new “line” suited the bike better. I reused the Maxim light and made a bracket to mount it and the number plate. Everything sprayed black and I got the result I was looking for. The remaining/unused holes in the guard were fitted with black rubber blanking plugs, these also acted as rubber dampers for the rear number plate. I thought this better than welding or filling the holes prior to painting.

The attached image of the rear end shows: the Seca, a standard 4U8 and my alterations - What do you think?

I do plan on fitting some kind of grab rail or lift handles but not sure yet, what or how.