GS1000S VM Carbs Vacuum Line & Vent Hoses

[Guest]

Greetings to all from a complete newbie to GSR...

I'm in the process of restoring a 1979 GS1000S (Wes Cooley), and the previous owner has left me with a couple of fuel issues to sort out.

1. The innards of the petcock vacuum diaphragm arrangement have been removed and an inline fuel tap installed instead.
2. All three hoses at the back of the carbs (one of which would be the petcock vacuum line) have been blocked off with screws.

Searching threads suggests that the vacuum petcock hose should be connected to #3 on VM26 carbs. Is this correct? I know I can test it for vacuum while the engine is running, but I'd rather get it right before then.

Also the other 2 hoses are presumably vent lines - they're currently blocked off with screws. Should they be open to atmosphere? It was running O.K before I pulled it down, so I'm confused about the function of the vent lines.

All and any advice gratefully appreciated.

[hampshirehog]

You're right that the vacuum hose connects to number 3 on the nipple head side of the carb body.

You should open up the vent nipples, preferably by popping on some hoses that run back over the airbox. The vents ensure that unequal pressures don't build up inside the carbs.

i presume you're fitting a new fuel tap.

[Guest]

Thanks for the confirmation about the vacuum hose.

There are already vent hoses on 2 and 4 so I'll just remove the screws from them.

A new fuel tap is waiting to go on.

[Kiwi Canuck]

Welcome Sealpup, we have a lot of members who own "Wes Cooley Replicas" on this site.

I am building a list for all the known GS1000S's, I would appreciate if you could either PM or post your VIN (frame #) and engine number.

BTW we love pictures.

Thanks.

David

[steve murdoch]

Welcome to the site, sealpup.
Of course we will need pics of your S.
David aka Kiwi Canuck is compiling a registrar of S frame and engine numbers. It would nice to add yours to the list.

[Guest]

Hi David,

1979 GS1000SN, Engine No. GS1000-147595. Frame No. GS1000-530300

I'd be interested to see make you make of the engine number/chassis number combination.

Thanks for your time.

ps the bodywork is away getting painted at the moment - I'll post some happy snaps when it's all back on the bike.

[Kiwi Canuck]

Hi David,

1979 GS1000SN, Engine No. GS1000-147595. Frame No. GS1000-530300

I'd be interested to see make you make of the engine number/chassis number combination.

Thanks for your time.

ps the bodywork is away getting painted at the moment - I'll post some happy snaps when it's all back on the bike.

Looks like you have a 1980 model there, (unless Suzuki used a VIN from the 1980's on a '79) can you check the date of mfg on the headstock label, it's probably very late 1979.

Does your bike have a square front brake reservoir?
Like this.



How about the foot pegs and gearshift are they set back.

Like this.



If so you have a 1980 GS1000ST then.

Also slotted rotors are another tell tale sign on the 1980 model.

[Kiwi Canuck]

Pretty sure it's a GS1000ST

Pretty sure you have a 1980 model there Sealpup, I have a few others just around your VIN and engine number and all 1980 models.

Cheers,

David

BTW thanks for the numbers, every set fills in a missing spot on my list.

[Guest]

David,

Is it the chassis number or engine number that steers you in the 1980 direction?

My GS has the '79 dash, seat, carbs, front brake calipers, self-cancelling indicators, etc. Though after 35 years and countless owners/crashes it may have become a mongrel.

[Guest]

Sorry, I missed a few replies below the one I responded to...

The headstock label says "12/79". Front rotors are solid - not slotted. Front master cylinder was an aftermarket unit, though I'm restoring a round reservoir unit to put on.
Gear lever is mounted direct onto shaft - no rear-set linkage. Foot pegs are also not rear-set.