wes cooley bike - carbs

[Guest]

hi everyone,

i have a gs1000 st model 1980 with the slide carbs.
screw.jpg
i have taken the bowls of,
to inspect and clean.....as the bike was running on two cylinders
despite spark to all 4.

the photo is of one of the carbies from the bike.

question:
can any member in the know, help me identify and name the brass
screw shown in the photo and what is it used for?

the parts list diagram does not have these shown and yet they are the same carb.

upon opening the fuel bowl i see these screws (one to each carb) that are located
on the opposite side of the float valve.
they each were not tight (about a quarter turn out)
are these meant to be tight?

the pipe and jet were taken out and cleaned
as the bike was running on two cylinders.

many thanks in advance

[zed1015]

Those are fuel mixture screws.
They are not meant to be tight but are pre set at the factory individually for each carb.
Your running issues are likely to be due to blocked pilot jets but it is also common for the tips of those fuel screws to break off and block the outlet orrifice in the floor of the venturi and cause the same problem.
This is usually caused by overtightening of the fuel screws or bi metal corrosion .

[chuck hahn]

TUTORIALS here on rebuilding and removal of brome pilot screw tips.
If you have an 80 it wouldnt have VM carbs, 8os had CV carbs

https://gsarchive.bwringer.com/

[Rich82GS750TZ]

You must take the carbs off the bike and completely disassemble to clean properly. Anything less is an exercise in futility. Guides for both VM and CV, whichever you have, are on BikeCliff's Website, linked by Chuck above and also in my signature.

[Guest]

thanks for the replies....much appreciated.
the bike definitely has the vm slide type carbs.....and it is a genuine 1980 ST bike.
i will take these of to clean properly...
i remember once doing z1300 cv carbs and they were a nightmare to put back in....
is there an easy way to take these out / or put back in?
any tips?

[rphillips]

Just wondering, He's in Australia, I wonder if their CV carbs came later than U.S....Picture shows rear sets, that indicates a true "80" model

[Rich82GS750TZ]

Kiwi Canuck would know. If memory serves, he's the resident authority and had been keeping record of all of the various 1000S bikes sold in various markets.

[Big T]

VM carb removal is easy Remove side covers and fuel tank
Remove air filter box by unbolting the rear master cylinder reservoir and let that hang
Loosen all 8 screws holding the carb rubbers to carbs
Remove the 2 bolts holding the front air box to the frame
Then, slide the carbs to the rear and see if the front will clear the boots. If not, slide the carbs back in the boots and gently work the air box rubbers down the back of the carbs. Rotate the back of the carbs upward and continue working the rubbers down until the carbs are freed.
slide the carb rack out the right side and detach the throttle cables.
That's it

[Kiwi Canuck]

Hello Met999, welcome to the GS Forum, if you could provide me with you VIN I can add it to the registry and possibly shed some light on the carb situation.

Australia sold the 1980 GS1000S well into 1981 and was dipping into the parts bins to build them, so we see a few interesting variations not found in North America or Europe.

BTW what size rear wheel does your bike have and are the instruments standard type clocks or housed in the "S" Binnacle.

David.

[uk gs nut]

Looking at the picture of the bike, those carbs look like VM29. Check the square casting on the side.

[zed1015]

Looking at the picture of the bike, those carbs look like VM29. Check the square casting on the side.

Correct.
Those are VM29MM Smoothbores.
The brass floats in the first post are another giveaway.

[Nessism]

To my recollection, VM29's don't have pilot fuel screws.

It's my understanding that in various different places in the world, Australia for example, Suzuki installed VM30's on the later year 1000S bikes. Those bikes had bigger cams and a better flowing exhaust too. The IP cluster looked like the 1000E, not like the S from others locals. A unique bike.

[Guest]

hi again.
i believe they are vm30, but as Nessism says, here in australia these bikes differed a lot to those from abroad....there was no set rule and the variations were many.....so i believe. the most obvious being the quite different paint job patters of the aussie bike.....both of my two wes cooley bikes are identical...both red and white and both 1980 models and both with vm slider carbs - im just having trouble with this one at the moment....
Kiwi Canuck the vin numbers are gs1000-534351 built 10/1980 for this one .................and gs1000-535252 for my other one
both have 18 inch rear wheels and both red line at 9000...many thanks
do we know how many of these st's were made by the way?

[Kiwi Canuck]

Hey Marc, thanks for the VIN's, I do have one of your bikes already in the registry, but the other one 535252 is the highest VIN I got so far.

The "T" model year (1980) started at VIN 528511 so your bike is the 6,741 GS1000 produced, (which includes ET's as they used the "53" prefix as well)

I have guesstimated based on the data I have so far, they produced about 7,000 units for the SN and 5,000 units for the ST.

Interesting to note you have 18" rear wheels as some of the later bikes did get 17" wheels from memory.

Good luck with sorting the carb issue.

David.

[Guest]

hello again.....i am considering going down the option of getting new carbs for at least this one bike of myn....the new mikuni rs 34 i believe which are 40mm.

my question: is there anyone that knows of this mod. is it successful and a common thing to do for these ageing carbs, any pros and cons. any comments will be appreciated