GS650GT Rebuild

[nowhere.elysium]

Right - I'm not gong to do a complete re-write of the original build thread, but I'll cover the highlights.

Here's how I found the bike initially; it'd been laid up in my Dad's garage for twenty years.
Anyway - got it loaded up into a van, so I could start working on it.

So, I got it to my garage, and gave it a proper looking over; aside from a ton of dust buildup, it looked OK generally.
I decided to use an endoscope to have a look around at the state of the tank - given that it'd been left with half a tank of four-star petrol for twenty years, I was expecting some serious filth to have manifested itself.

...And I was not disappointed. I'll get back to that later with a proper acid strip.
Moving on, I did have a bit of scrubbing to do, since the cases had succumbed to the famed British weather somewhat.

After some serious application of WD40 and wire wool, I managed to get a significantly better finish:


In other news, the clutch plates were still sound, which was pretty awesome - I'd have predicted seizure, given the period of time that it had been sat.

I was also pleasantly surprised by the state of the forks: ordinarly, I wouldn't endorse the use of gaiters, just because they're questionable as hell, but they did a good job here:

Things like the air filter, however, didn't fare so well:

Nor did the seat pan, unfortunately.

Fortunately, that was pretty much the only notable victim of the great and terrible God of Oxidisation. It didn't help one bit that they were unavailable, though - I couldn't find one on eBay, and NOS just wasn't going to happen. Luckily enough, someone managed to spot a pattern one one a german ebay page, so I snapped that up sharpish.

Moving on; I decided to do the obvious partial stripdown, just to see what I could get sorted.

[nowhere.elysium]

Dropped the oil, and it was distinctly less emulsified than I feared.

There was, however, a whole ton of prime 1980's road filth caked all over it, though: I honestly thought these coils were black when I first looked at them.

It may not be totally clear from the picture, but there was a whole ton of filth all over the place on the bike

Decided to try to drain the float bowls, just to see what kind of horrors were contained therein.

Having seen the lurid evacuations from the float bowls, it occurred to me that there was a high chance of the fuel tap being blocked. Suffice it to say, I was not disappointed.

Moving on to the electrics, I stripped down the switchgear, in the hope of getting the starter button to work.



On a somewhat depressing note, this is how the switchgear internals came up after a comprehensive cleanup.
On to the carbs: as I imagine many of you know, Suzuki employed a singularly horrible airbox design, which was still in use by the time the Bandit 6 came out, so they clearly hate their paying customers. After spending several hours shouting incoherently, and offering small sacrifices to the God of Home Mechanics (he seems to enjoy offerings of blood, knuckle skin and fingernail shards the most), I finally got the damn things off:



On the initial stripdown, I got most of the obvious chunks of tarry goop out, as is evidenced by this photo:

[nowhere.elysium]

Of course, the whole acid-strip thing made for a pretty rank sight:




More to follow a bit later on.

[recycled64]

Seuwpah!

Great posts and great pics, great bike, too!! (Japanese designers of the day seemed think Brit-bikes had to have gaiters!)

[cowboyup3371]

I hope the missus won't complain about that tub too much

[Charlie G]

I know there is some engineer that designed that air box, who is laughing his arse of about all the pain he's inflicted on us with 650's. Thanks for sharing.

cg

[overboostin]

What did you use to clean off the majority of the road grime off the bike? Also, when you used the wd40 and wire wool, did you spray the wd on as a lubricant and rubbed that?

[nowhere.elysium]

The gaiters were actually my dad's choice - he figured that since it was going to have to endure a few British winters, it wouldn't be a bad idea. Not often I agree with the idea of gaiters, but this is that one instance

We got the worst of the filth out of the bath pretty sharpish, precisely because I was getting the evil eye. Fortunately, the chunks were pretty big, so after being rinsed through with water (because who wants to go poking phosphoric acid?) I got the worst of them out and into the bin.

As to the engineer, I'm hoping that he had the dubious pleasure of stripping down one of the bikes that he designed. They are a nightmare; the worst thing is, I may have to remove the carbs again some time soon, and I'm dreading having to sod about with the plastic box of misery.

The engine cases were done by spraying WD40 directly on to them, and also on to the bundle of wire wool. Previous to that, I'd sprayed a ton of aerosol degreaser on there, and scraped out the bulk of the initial muck. There was a lot of muck. Britain was a pretty grubby place in the 80's

Speaking of the airbox of rage and despondency, I'm going to do a direct copy of what I actually wrote at the time to describe the process:

Observe: a rubber trumpet.



Behold: the horrible airbox that houses said trumpet(s).



Gasp in shock and dismay, at the bastard innovation of a sprung metal clip, that sits inside the trumpet, while within the grasp of the airbox.



It may not look like much, but going from this^ to this:



and subsequently this:



was no mean feat.

With part one of the airbox complete, I thought I'd take stock, and look at the rest of my task.



This was the cavernous void that required refilling, and refill it I did.



This last photo deserves a little explanation.
After much swearing, and a great deal of knuckle scraping, The carbs were convinced to make friends with the the cylinder head. However, I then tried to reapply the airbox, only to be met with failure. Further swearing occurred, and I finally admitted defeat: the carbs had to come off again. So, off they come, (not easily, mind you), and then the airbox is put in situ, followed by the carbs. A further 20 minutes was spent shouting at small rubber objects that wouldn't go back together for love nor money. Finally, after much cajoling and pleading, the little rubber things and the fiddly alloy things all decided to make nice, and sit together happily between the airbox and the cylinder head. This brought me much relief.

But yeah, basically the airbox and the carbs were complete gits to refit.

[nowhere.elysium]

I had a properly manly struggle with exhaust bolts (bolts, mind you; not studs), and this occurred:



I prevailed, though, and the result was:



That's a shedload of steel right there. I could probably weight it in for scrap and get a good few quid for it.
Anyway, I'd received the new exhaust, from a small company called Predator. I tell you now - if you ever order an exhaust in the UK, don't order it from them. The reasons why are as follows:



Aside from the collector box looking rubbish, the downpipes didn't want to sit properly:



The header plates didn't fit properly, either - I had to have at them on a grinding wheel to get them to sit right. After all that, I finally got the pipes to sit correctly:



Or so I thought...



I sent that photo to the manufacturer, and they insisted I was doing it wrong. After a great deal of to-ing and fro-ing, they admitted culpability, and it came out that it was actually a system that was designed for a GSX550. I regaled them with a few choice words, and got my money back.

[nowhere.elysium]

Jumping back in time a little bit (thanks to my exhaust rant, it's out of sequence, but I can't imagine that's a huge problem), I got my tyres delivered - had to take them home on the back of my SV, though, which made filtering highly entertaining.


Anyway - shock fitting:



Rear wheel removal. Not a tough job if you happen to have a spanner in the right size. I didn't, but managed to get around that with a tool loan.



It's clearly never been off prior to this



Rear brake with bonus fauna, and a ton of pad depth left (great success!)



...And how we'd left her for the time being:



Looking slightly sad, but it was only while we sorted the tyres. Oh God, those bloody tyres. I tell you now, Slime might seem like a good idea on the face of it, but after twenty years, it's an entirely different story.



Nice.



That was so much fun to scrape off.

[nowhere.elysium]

By this time, the new exhaust had arrived: A Marshall/Jama 4 into 1.



Unlike the Predator abomination, it took about half an hour to fit.

On a side note: whoever invented JIS screwheads should be flensed. You can't get JIS bits in the UK anymore, so I had to make do with a set of ACR bits, kindly acquired for me by a fabricator friend of mine.

The rebuild was then interrupted by the London Riots, which were not the most fun times to live through.

After that, most of my problems were electrical, which don't make for good photo opportunities, I'm afraid.

I ordered up a new set of coils, because the ones that were already on there were only just within spec. However, I learned an interesting thing: coils are sold according to their physical dimensions, i.e. the eye-to-eye measurement, not their impedance value, which is stupid and unhelpful in the extreme. The ones I was sent (which were listed as being for a GS650GT) not only didn't fit, but were of completely the wrong rating.

I decided to run with the coils that were already on there, purely to save myself any further hassle. It transpired (thanks to an electrical engineer's assitance) that the pickup plate might be shagged, so I ordered the only one I could find on eBay - it was from Alabama, and took over a month to get here. Imagine my frustration when a week after it arrived, someone decided to part a GS out in Bath (~120 miles, as opposed to several thousand miles away).

Moving on, some time elapsed, which was largely filled with me removing and refitting the carbs several times, in an attempt to get them to do what they were designed to do. We finally got the thing to fire up with the aid of easy-start, which turned out to be a bit of a mistake. My mate was cranking the bike over, and I was spraying the easy-start into the airbox; however, he decided to blip the throttle, which caused a significant backfire. A beautiful (and, to be honest, bloody terrifying) fireball was ejected through the airbox, taking most of the hair off the back of my hand.



I'm pretty damn hairy, so that was something of a blow to my masculinity; having to walk around with one hairy hand, and one frizzy hand. After that entertaining escapade, I decided to give the carbs a total strip down, just to see what was going wrong in there; it was consistently failing to idle, so I assumed that there was a problem with the slow circuit and the mixture circuit. I'll let the pictures do the talking from here, because my takeaway's just arrived







Yes, that pilot jet is quite significantly blocked.

[nowhere.elysium]

It was at about this point that I discovered this site, and promptly found out that I'd gotten the hose arrangement on the carbs slightly wrong - I'd joined the two vent hoses, thinking that they might be vacuum lines instead. I have no idea how I'd come to that conclusion; I'll just chalk it up to my first genuinely stupid mistake in the rebuild.

The second stupid mistake was also uncovered by reading around on here: inline fuel filters don't play nicely with the 8-valve Suzi lump. Once I'd gotten that out, and got the carbs back on, it roared into life. I've still got to balance the carbs and set the proper fuel/air mix, but other than that, it's running beautifully. I've already put 400 miles on her in the past fortnight, and the only problems that have manifested are crap idling, and overly water-sensitive switchgear.

[BigD_83]

Hopefully, mixing up the carb parts doesn't cause you any grief. Due to particular wear patterns, it's usually best to keep the needles and jets in the carbs from which they came.

The only problem the inline filter has caused for me, is a massive softening of the plastic of the filter housing. It was bad enough that I removed it for fear of failure, in the same spectacular fireball sense as you mentioned in one of your previous posts in reference to the airbox.