Freebie GS550 Katana

[PeteClem]

Hi everyone, new here.

Last year a mate of mine gave me a 550 Kat. Luck bugga you might say. Well, when I started to get stuck in there was allsorts missing, and parts from a different older model GS550 but I thought , well its cost me nowt. So Ive spent the last few months collecting bits & bobs from Eblag, online shops, jumbles, fb marketplace and now somewhere near the point where it can start to go back together. 

First question I have is does anyone know know if its possible to find the original UK reg for it from the frame number. I've contacted the DVLA and it looks like I should be ok to get an age related one , if not it will be classed as a reconstructed vehicle and will be given a Q plate, which will at least get back on the road.

Question 2. Carbs. It also has two sets of carbs, one old style slider set and a CV set. I assume the CV set are the right ones for the bike but would the slider ones also fit if I get the right diameter carb inlet rubbers or will I need an older head to make it work. or is that just a daft idea..

Any help much appreciated, Thanks in advance. Cheers Pete

Pic is the day I picked it up

Edited March 18 by PeteClem
missed some txt

[DAZ]

Hello and welcome to OSS. 're the reg number, I've heard that if you've got a friendly bike/car dealer they maybe able to get you the original reg number from the frame number via a traders hpi check , would be worth asking at least . As for the carbs I would see what intake rubbers you can get to start with..... Can't see Suzuki San altering the port spacing 

Edited March 18 by DAZ
Addition

[PeteClem]

Hi Daz, and thanks for the warm welcome. That is a good point, I'll look at carb intake rubbers first. As for the Reg, I don't know any car dealers, but it costs nowt to ask so thanks for that little tip. I've more or less come to a dead end with everything else I've tried. I've sent a few emails to the Suzuki UK owners club and not a whisper back from them. Someone on another forum somewhere suggested the Vintage Japanese Motorcycle Club so might try them at some point.

 

Cheers

[Guest]

You can sometimes get the original reg number if you have the frame number by applying to DVLA, but I understand they need to see pics of a complete bike.

Otherwise you can get a dating certificate from the VJMC and apply for an age related plate....better than a Q plate.

Port spacings are different from CV to slide carbs on other Suzukis, so I'd assume the 550 is the same. Stick with the carbs that match the head.

VJMC Dating

Edited March 19 by Guest

[wraith]

Welcome to OSS 

As said  try VJMC for reg/age of bike etc

Carbs, different port size and spacing between the slide carbs and CV carbs.

So if  you have the kat 550 engine that will be CV carbs I'd stick to them, and trying to find a good slide carbs head will be hard and the cam covers are different as will 

[PeteClem]

Thanks Wraith, that's the kind of info I needed about the carbs/head. I do have an old style cam cover and camshafts in amongst all the odds and ends, but not a head. The head I have is  ( or at least looks} complete and in decent nick, the cam chain is OK and the crank seems to free and smooth with no play on the big ends. I've also  got a set of carb rebuild kits for the CV ones and some inlet rubbers for those , so based on all that the CV ones look like the way to go, so cheers for that. Regards the No plate, a few folk have suggested the VJMC. It would seem they can get info MIF cant ha ha.

[Guest]

You're welcome 

[Enjoythesilence]

Hi there,as said before-i have got registrations from frame numbers with my local bike/mot shop doing a hpi on them and i bung him a drink,better than paying dvla

[PeteClem]

Hi again everyone. another quick question to those knowledgeable about all things GS. I'm hoping to put the engine back together soon but I have a question about the clutch push rod. There seems to be two different types, one complete and another which appears to be in two pieces , of which I think is missing, the outer piece that goes through the sprocket cover casing.

 

Am I right in thinking this , or completely off. If this is correct, does anyone know where I might get the missing piece, have one they could take a pic of so I know what I'm looking for , or that they might be willing to part with.

 

Alternatively, am I able to just use the longer one, with the screw worm on the end, which I think seems to be from an older model. It was just in amongst all the parts and I thought it was the correct one for the engine until the engine was stripped to check it over.

Any help welcome, thanks in advance, Pete

[ral]

Well worth getting a good workshop manual and a good source of info is to look on part suppliers websites, search the part finder schematics for your  specific model and year the diagrams will help to identifying what components make up say a clutch for example.

Good luck with your build.

[Guest]

The pushrod on the 550 was changed from 1 piece to 2 piece, check CMS parts books for the details as said.

The part was superceded, meaning you can use either, assuming it's  the right part, not just a random one.

It's just a rod....as long as it's the right length, it will work. 

My GS425 uses the same rod, and currently has piece of plain hardened steel rod and works fine. I couldn't find a new part, and mine was badly worn where it works on the oil seal.

I've got a later model 550 2 piece rod to go in at some point.....as the 425 was short lived, the part was never upgraded in the 425 parts book, but obviously it must work. The later 550 pushrods are available if you search hard enough using part numbers.

[PeteClem]

Hi all, been away from here for a while as I got sideswiped with another bike thats been a right nightmare that I took in PX for my Z750. Thats now at the back of the garage until I want to be friends with it again. I have another puzzle for the Suzuki wise. I recently picked a complete bottom end, checked it over and it all looks good, and have got as far as putting the barrels on. I plan to take the head and cam cover to get cleaned & blasted somewhere later today but I have a part tha I'm not sure if its even off one of these bikes, it was just in amongst the bits with all the parts for the head.

My best guess is that its part of the cam chain guide system , but not altogether sure.

 

This is the little fella, along with it in my best guess at where it goes as thats the only place I can think it might fit.

 

All help welcome gentlemen, and many thanks. Pete

[PeteClem]

PS, I cant find it in my Haynes manual or on the Fowler parts schematics. Cheers

[wraith]

1979 gs550 

[PeteClem]

Ahh. Thank you Wraith.

OK, I went to the page from where this pic comes from and it must be from the bits from the older model spare parts. I went to the GS550, 1979 listings, found it then went to the 1982 GS550M Katana listings and its not in there so must be from a earlier model and the later ones don't have them in. 

Or at least that's what I'm assuming. Please correct me if I'm wrong.

[PeteClem]

Couple of questions again.

First one. Amate has loaned me a Ultrasonic cleaner. Anyone know what the best stuff is to use for cleaning carbs?

Second. Anyone tried painting over powder coating and has it worked. If it dosen't, how could I get it off?

Lastly. Would a GS650 cylinder head fit on a 550. Only wondering as there is someone near me selling a complete 650 engine for £75.

Cheers all.

[PaintItBlack]

6 hours ago, PeteClem said:

 

Lastly. Would a GS650 cylinder head fit on a 550. Only wondering as there is someone near me selling a complete 650 engine for £75.

Cheers all.

You can fit the whole top end from the 650, barrels pistons etc onto the 550 bottom end,

mate of mine did this on his 550, 30+ years back, worked really well, the 650 is actually around 670cc, so quite an upgrade 

[PeteClem]

So, if I were to try the 650 top end, would I need the carbs & pipes too, and possibly the igniter box?

If thats the case, I'll just leave it. I at very least need a cylinder head gasket, just bought a full 550 kit, some of which I've now used building the bottom half up.

[PeteClem]

Hi all. Would anyone have a valve retaining collet spare for a GS550. Looks like I've some how managed to loose one, I've only got 15. CCheers

Edited August 18 by PeteClem
misspelling

[PeteClem]

OK, change of plan. Managed to pick up a complete head in much better nick than the one I have complete with valves and camshafts, ready to go on. 

However, the carb rubbers I have are a bit bigger in both mounting hole spacing and port size.  Its the same shape as the Katana one otherwise, having the extra bolt in front of the cam chain tunnel, which was not the case on the bike the lad had on the engine in his GS550 that I got it from, which is an older model.

Therefore I'm guessing that its from a later model, but would anyone have a clue as to which one it could be or be able to let me know how to work it out so I can get the correct carb rubbers.

I have two sets of carbs, a older slider set and the Kat CV ones, so hopefully, one of them will fit.

Thanks in advance, Pete

[PeteClem]

Hi aal Rebuild got de railed for a while, hopefully back on it now.

 

First question. Does anyone have a basic wiring diagram for the CDI box/coils/pickups only, by passing the rest of the wiring which I'm going to have to strip right back and 'make good' as so much of it has been hacked up. I just want to link up the ignition parts to try to get it to run.

 

Cheers Pete 

[Suzukian]

What year is your bike?  All pertinent information, exact model.   I have a manual, but I need exact information so I can give you a Google Drive link so that you can get the right manual .:)

[PeteClem]

Hi Suzukian, thanks for the reply.

Bad news is I dont know any exact info as I dont know the reg number, but if it helps Ive got the frame number. The engine is a build up of more than one , I know its the wrong one as it takes slider carbs, I was just hoping I could use the ignitor box /coils etc that I have from the Kat to get a spark to fire it up. I do have the CV carbs, and the head but they need building back up and the head needs some repairs, snapped studs. The head on it must be from one of the later slider carb models as it fitted straight onto the Kat cylinder barrels, having the extre bolt at the front of the cam chain tunnel. The older ones dont look loke they have that bolt, but thats just from what Ive found online.

Not much help I know but I did get it given and I'm in no rush so anything you can put my way will be grateful for and willing to give it a shot. Cheers Pete

[PeteClem]

Hi all. Quick one. Is using 8mm thread bar for exhaust studs ok or a bad idea. Cheers

 

[wraith]

On 11/30/2025 at 12:00 PM, PeteClem said:

Hi all. Quick one. Is using 8mm thread bar for exhaust studs ok or a bad idea. Cheers

 

Not really a problem