Carb

[01Silverado]

Hey all, I bought a pretty rough GS750 w/ a 1000cc motor in it. I took the carbs apart and had a few questions.

I know the center jet is the Main Jet. What is the jet to the left of it?

What is the needle jet above the main jet? One of the needles was bent, pic. The other needle is broke and lodged in the hole. Any ideas to get that out.


Bent Needle
`


2Ports

What hoses hook up to these 2 ports? Its only on one of the bowls.




Bowl Port/ Weight

Last, what is this little weight in one of the bowls?

Thanks for all the help.

[01Silverado]

Anybody know how to get that broken needle out?

[psyguy]

to get the needle out try using an "ezy out" bit, its like a reverse drill bit

btw,those carbs are not from a 81 but 79 model or older
i'd check that you have the right jets for your setup while you're in there
have a look at the sticky carb specs thread in the tech forum if you dont have a service manual

[hampshirehog]

jets: 1 is the main jet, 2 is the pilot jet and 3 is where the fuel meter screw goes.

Those bent / busted screws are fuel meter screws.

To get the busted tip out try:
Punching out from inside the carb using a very fine punch.
Blasting out with a compressed air gun pushed in hard.
Boiling in a saucepan of water might free the bust bit on it's own but is useful in conjunction with above.

The odd float bowl is off another set of carbs - way earlier design - and the tubes should be blanked off if they work on your bike.

Bearing in mind that you've got mis-matched carbs + you'll need to replace those fuel meter screws (which I don't think you can buy separately) I'd start looking for another set of carbs if I were you.

[80GS750]

i have no clue whats up with the ports on that bowl....

none of mine have them like that....

definately not supposed to be there.

well add your case to the list of dumbarse PO's

[01Silverado]

Is this the air screw?



What is a good starting point for the air screw and the fuel mixture? How many turns?

So if I order parts I need to say they are from a 79 GS1000?

Also, what year and size engine Carbs would transfer to my engine, 81 GS1000?

Ill try to blow out the broken needle this weekend.

Thanks again.

[80GS750]

yes thats the air screw only.... theres a fuel screw on the bottom of the carbs too....

you would need parts from a 79 gs1000 for that motor and carbs...

in 1980 they went to CV carbs... so 78-79 carbs would work easily, and i think you can switch to CV carbs but im not sure what you have to do to swap

[80GS750]

get ahold of keith krause on here, he will know how to set them up to get it running initially... once you tear them apart and clean them good, and then replace all the O rings in them

for O rings talk to Robert Barr on here, he sells them for your VM carbs for cheap!

you'll need O rings for the manifold boots also.....

[psyguy]

iirc, gs1000 from '80 onwards runs mikuni bs34 "cv" carbs
you can find them on ebay from time to time

but with the pod filters and 4-1 pipe you are going to need new jets and needles anyway so it may pay to tear your carbs apart and see whats in there and order individual parts

do a tech forum search for the screws settings, i think something like 1.5-2 turns out on both screws should be good enough for a start

[Suzuki_Don]

To change to CV carbs you will need a later model 1000 cylinder head. The CVs have bigger ports where they fit onto the head.

[Nessism]

iirc, gs1000 from '80 onwards runs mikuni bs34 "cv" carbs
you can find them on ebay from time to time

but with the pod filters and 4-1 pipe you are going to need new jets and needles anyway so it may pay to tear your carbs apart and see whats in there and order individual parts

do a tech forum search for the screws settings, i think something like 1.5-2 turns out on both screws should be good enough for a start

A good starting place is 1 turn on the fuel screw and 1-3/4 for the air screw.

In case you didn't know there is a VM carb cleanup series in The Garage linked on the GSR homepage.

Good luck.

[renobruce]

Those ports on the bowl are for an accelerator pump set-up found on some of the VM28 carbs. You have a mis-matched set, or someone used that bowl as a replacement.

If the carbs were already mounted on the engine, then you have a 78 or 79 motor. You can't put CV carbs on a 78 or 79.

Does the bike also have a 4 into 1 pipe? Check the main jet size and let us know what it is.

Do a search for "broken pilot" and you will see some threads with instructions on how to get the broken tip out.

[Suzuki mad]

iirc, gs1000 from '80 onwards runs mikuni bs34 "cv" carbs

Suzuki GS1000 up to 1980 (EN model) were VM carbs. With the arrival of the GS1000ET the bikes went to CV carbs. There are also other model differences that can tell you if its a EN or an ET if the bike is fairly standard.

Looking at the carb bank picture I would suggest that no 2 from the left is not of the original bank of carbs or somebody has changed the float bowl. Even looking at the Suzuki workshop manual its not showing what you have there.

Any chance you can post a picture of the broken 'adjuster.' Just hope that nobody has snapped it off doing it up too tight. Might be a b**t**d to get out.

Suzuki mad