'77 GS750 rebuild... continuation

[Guest]

Hi, My name's Tom, I live in the UK and have just bought a half finished GS750 project to finish off over the winter (hopefully). The bike was first registered in UK in November '77, but I'm still trying to work out which bits are original and which bits fitted by previous owners.

The plan initially was to sort out a few remaining issues; new chain, battery, brake pads, carb clean and get her through an MOT test. I'm after a reasonably tidy, functional bike - doesn't need to be all original parts. It would seem however that some of the previous work has been bodged quite a bit and I'm looking at a slowly expanding stack of jobs.

So here's where I'm at so far... I've bought new battery and got her started up, nothing sounds too bad, though there were a few understandable pops and bangs (carbs need clean and rebuild and exhausts need replacing) but it's good to know she can run. The exhausts seem to be from a GS550, with over-bent downpipes and a horrible looking mess around the exhaust studs. So I plan on buying a new motad 4-1 as soon as I can figure out for certain I'm buying the right set...
Clocks are off I guess some other Suzuki - when I can I'll post pic - speedo only goes to 80mph... Hmmm. Neutral, gear pos and oil lights seem to work tho. LH switchgear is also wrong, though it does work indicators.
Wheels are alloys, and front end is twin disk - which is confusing me a little as I thought '77 was single front disk and spoked. Maybe she's had whole front end replaced along with wheels?

I'm currently working on the easier bits while I find and order parts, so stripping down seized rear brake caliper and replacing hoses, then will be moving on to exhaust and carbs soon.

Couple of questions if anyone is able to answer; Can I fit GS550 clocks? (they're much more common and reasonably priced on ebay) and how can I identify model number (currently I'm assuming it's a B) so I know which exhaust to order? Any help very much appreciated

I'm in work right now so only have a pic taken on her first day in our garage, but I'll attach it here anyway as a starting point.

Cheers Folks, Happy riding,
Tom

[Tomly Tom]

Exhaust removal

Got home from work last night and decided the time had come to get those shocking old 550 exhausts off and start cleaning up what was underneath. I guess I got lucky in that all the studs/bolts came free very easily, revealing an interesting mix of methods which had been used to attach the wrong downpipes.
For the most part, the ports came clean with some (very careful and judicious) hammer/screwdriver work - but I'm a bit stuck on no.1 pot now which has a sleeve of some kind jammed and glued with exhaust sealer. The stuff is a lot like cement, and again using hammer and old micro screwdriver I've cleared most of the rubble...

but the sleeve is still very stuck

I'm open to suggestions on how to remove without damaging cylinder head, but have to point out my toolbox is somewhat limited. I've been considering investing in a dremel... would that be able to cut it out d'ya think?

Also, now that I've managed to figure out this photobucket thing I thought I should post a full size pic of bike:-

One other thing for now, I'm wondering if anyone can identify what model these clocks are from:-
Any thoughts and advice would be much appreciated.

[78gs750e]

I don't know if this would be the same in the uk but I think you have a realy early 78 E model where you would get dual disk front and alloys. The clocks look to be off a L model. In the us the 77 had a special ignition, clocks and wiring. They also had a sepreate steering lock on the stem. 78's and 79's had a steering lock as part of the ignition and the lock cylinder is centered.

[Tomly Tom]

steering lock

Thanks mate - I didn't know about steering lock, so will have a look tonight and see if there's any signs of mechanism (presumably there will be some evidence to be found around the stem somewhere, even if it's not connected to current ignition). The point about the E model is pretty much what I was thinking, so very grateful to have a more informed opinion backing up those thoughts. I still think it's possible it's a union of several bikes (more than likely including a US import) as some of it is way too clean and rust free for the UK.

Do you (or anyone else) have any idea whether the model (B,E etc) will make a difference to my choice of aftermarket exhaust? I've found two Motad 4-1 systems that look rather different in the pics:-

http://www.ebay.co.uk/itm/161167830955?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

http://www.ebay.co.uk/itm/130978689835?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

... the second of which says GS750D. I keep getting sniped on ebay trying to get the first (only place it's available), and am wondering if the second would be a bad choice if I get beaten to it again?
Thanks again for any advice you can offer,
Tom

[Charlie G]

I have a set of 78 750 gauges and they are a one piece unit which goes to 140 mph. I know of a 77 750 in town, who's owner told me the 77's were unique in that the lock was built in to the one piece clocks and were hard to find. I believe the 80 mph speedo came into use in the states in 1980 and is quite similar to the one I have on my 650g and the one you have on your bike. Take a look at this link for model year identification by serial number: http://www.ozebook.com/compendium/su...-nos/page2.gif

cg

[Tomly Tom]

GS750 identification

Thanks Charlie,
Unfortunately your link was broken, but prompted by your reply to look further, I came across this:-


It seems to suggest that mine is a B (or at least the frame is) as from what I remember of the frame number it is GS750-18*** (can't remember the rest and I'm at work right now).
The 80mph thing is a bit of a relief actually - I had it in my head that it had probably come off a much smaller bike having no idea of the US change, so again thanks very much for the info

[Tomly Tom]

repeat with photos instead of links...

Hi Again,
I've done a bit of work this weekend un-seizing the front brake master piston, and a lot of work sourcing and ordering various parts (including brake repair kit).

On the subject of the steering lock, I've taken a couple of photos...


which suggest to me that as suspected the frame is original UK '77 (B?) with fittings for steering lock on column, but clocks are probably from '80s (ish) US model. Probably the whole front end has been replaced together with clocks and switchgear. I'm guessing this as the LH switchgear seem to have no headlight switch (but do have a choke lever) and from what I can make of various wiring diagrams (thanks BikeCliff), the US models were wired to have headlight on all the time (?). If any of you can confirm I'd be grateful

Oh yeah, and the other little thing I got done was removing the half welded in "sleeves" from exhaust port

Now I just have to get a successful bid in on new exhaust... Hoping the Missus won't cotton on to how much money I'm spending right before Christmas.

[steveb922]

Hi Tom,

I've been trying to work out what you have there. As others have said, the clocks are from a US 'L' model. Or maybe a 'T'. Definitely American anyway. The chrome headlight bucket probably came from the same bike.

The twin front discs and cast wheels indicate an EC or EN model. But the flat seat was fitted to the B and C models.

Unfortunately the steering lock isn't a good indicator of model. Although the steering lock system was changed, the bottom yoke stayed the same (with fixing holes) through to the end of the 79 model run.

What does the sticker on the left-hand lower fork leg say? I'm not familiar with US registration regulations, but I've seen similar stickers on other US bikes.

Assuming the frame number matches the log-book, I'd say you have a B (possibly C) with a good dose of later imported E* model.

[Charlie G]

I can say that at least 80 and later models had the headlight on all the time on US models. I bought a 77 GS 400 new, but can't remember it's headlight set up.

cg

[Tomly Tom]

Hi Tom,

I've been trying to work out what you have there. As others have said, the clocks are from a US 'L' model. Or maybe a 'T'. Definitely American anyway. The chrome headlight bucket probably came from the same bike.

The twin front discs and cast wheels indicate an EC or EN model. But the flat seat was fitted to the B and C models.

Unfortunately the steering lock isn't a good indicator of model. Although the steering lock system was changed, the bottom yoke stayed the same (with fixing holes) through to the end of the 79 model run.

What does the sticker on the left-hand lower fork leg say? I'm not familiar with US registration regulations, but I've seen similar stickers on other US bikes.

Assuming the frame number matches the log-book, I'd say you have a B (possibly C) with a good dose of later imported E* model.

Thanks Steve (and Charlie) all very helpful info. There's a photo here of label on forks, but I'm afraid it's unreadable in it's entirety, and the photo flash doesn't help. The only thing that's legible though are a few numbers at bottom - something - 22412 - something . There appear to be several layers to it where it's worn down...


On the same subject, I stripped down the front callipers this evening (by the quantity of brown sludge I'm guessing barn find front end) and will need to get a new piston/seals for one of them as it's seriously pitted. Do I need to figure out which precise model it is before ordering? In other words, does anyone out there know what the differences might be between the different models?

On a more positive note, I won my ebay bid for a new motad exhaust, and at a very decent price, about £120 less than retail

I think, amongst everything else I may need to replace gear lever return spring... Am I right in thinking this will be accessible from the opposite side cover (right hand side) without taking out engine and opening entire bottom end and transmission?

Thanks again to everyone who's been able to find time to think over my problems! I'd be totally lost without you guys

[Tomly Tom]

headlight

Incidentally Steve, how the hell did you spot the chrome headlight thing? Impressive observation skills... or "maybe you had some super-spy photo enlarger gizmo chingadaris doo-hickey" (quote from http://www.thegsresources.com/_forum...arshift&page=4)

[steveb922]

Basically, two different types of calipers were used. Up to '79 had round pads. '80 on had rectangular pads.

[Tomly Tom]

brakes

Thanks Steve - if anything that makes the assumption about the front end being all US post '80 redundant as both calipers have round pads, but it is exactly the info I was after concerning what piston to look for

[Druid]

I might be able to help with the brake caliper. I have a lhs caliper from a 77 GS750. I'm fitting GSXR1100 forks and twin discs to mine so assuming the caliper is the same as yours and it's the right side I'll sell it to you.



Looks like it's been recently refurbished, even has a new brake line.

[GateKeeper]

Incidentally Steve, how the hell did you spot the chrome headlight thing? Impressive observation skills... or "maybe you had some super-spy photo enlarger gizmo chingadaris doo-hickey" (quote from http://www.thegsresources.com/_forum...rshift&page=4)

probably by the first picture you posted...