Desperately need help

[kev edwards]

We are dealing with the the carbs with both air and pilot fuel screws here, so really need the manual that deals with this model of carb, specific to just one year or there abouts.

[zed1015]

We are dealing with the the carbs with both air and pilot fuel screws here, so really need the manual that deals with this model of carb, specific to just one year or there abouts.

If they have both air and fuel mix screws they are SUZUKI GS750/1000 and if this is the case they may also be either 26mm or 28mm carbs.
Kawasaki VM's never had both and only had either one or the other.
If they are Suzuki then lightly seat the fuel mix screw ( under the carb) and back it out 1/2 a turn.
Set the air mix ( on the side of the carb) at 1-1/2 turns out.
JWO261N
I would also like to see a pic of this other jet you say is present as there should not be any exterior removable jets unless they are air correctors which have been ruled out..

[JWO261N]

We are dealing with the the carbs with both air and pilot fuel screws here, so really need the manual that deals with this model of carb, specific to just one year or there abouts.

If they have both air and fuel mix screws they are SUZUKI GS750/1000 and if this is the case they may also be either 26mm or 28mm carbs.
Kawasaki VM's never had both and only had either one or the other.
If they are Suzuki then lightly seat the fuel mix screw ( under the carb) and back it out 1/2 a turn.
Set the air mix ( on the side of the carb) at 1-1/2 turns out.
JWO261N
I would also like to see a pic of this other jet you say is present as there should not be any exterior removable jets unless they are air correctors which have been ruled out..

2 pics attached

[JWO261N]

The one in this pic was installed in a range from all in to 4 turns out.
They’re all set to 1 1/4 turns out now.

[JWO261N]

The engine end is 26mm

[kev edwards]

26 mm carbs, set as Rob zed1015 says, 1/2 for the underneath screws and 1 and 1/2 for the air screws on the sides of the carbs, install and fire up, I guess float levels are set.

[JWO261N]

1/2 for the underneath ones
And 1.5 for the ones on the side.

Roger that ....

I’m just setting the ‘static’ sync for the slides now so I have a start point.
Any tips on that other than get them equal by eye?

[kev edwards]

1/2 for the underneath ones
And 1.5 for the ones on the side.

Roger that ....

I’m just setting the ‘static’ sync for the slides now so I have a start point.
Any tips on that other than get them equal by eye?

use a small drill bit in the carb throat to set the heights or take the tops off and measure the height of the slides in the body.

[zed1015]

Yes! Those are Suzuki VM26.
No sign of the additional jet you mentioned..
The fuel mix screws underneath were set individually at the factory and sealed for US emissions.
There is no book setting.
Which Keyster kits did you fit and which components did you change.
Compared to the Z's VM's the pilots on these carbs are on the large side (usually 20 ) whilst the mains are smaller (around 95 compared to 112 ish ).
Apart from air screws and float valves you should re-fit all the original Mikuni internals if needles etc were changed.
Ideally you would use a Keyster GS1000 kit if absolutely necessary.
As for bench "syncing" the carbs.
The easiest way is to just set all the slides so that the cutaway is level with the top of the venturi bore when the throttle is open but make sure you are mid way travel on the screw adjusters and that the slides fully shut with the idle screw fully backed off.
Bench syncing only sets a baseline but doesn't ensure correct cylinder balance until vacuum adjusted.

[Philippe]

Hi JWO261N

OK, so now we know you have 26 mm carbs, but they're from a Suzuki..., never mind, do as Zed1015 said.
Download the Z1000A2 manual . There's a chapter on bench synchronising the carbs . Read it carefully and apply the recommendations given in there. Don't forget to set the idle screw halfway before starting the synchronising of the valves. This way you have enough play one way or the other.
Do the static synchronising very carefull, if neccessary start allover again. If you do that correct, the carbs will need just a little adjusting after installation on the bike when using vacuum gauges.
Make sure that the readings on the vacuum gauges is correct !!!! They often give different readings so use only one gauge and start with the third carb. Synchronise the rest of the carbs to that one, using the same vacuum gauge.
When using only one vacuum gauge, make sure that the other three intakes are blanked off or you'll get false air.
Good luck with it!
GrtZ
Philippe

[zed1015]

only one gauge and start with the third carb. Synchronise the rest of the carbs to that one.
GrtZ
Philippe

I have to say that these VM carbs do not have a fixed register carb as some do (mainly CV's) with one carb having no adjustment on the link mechanism
As long as there is sufficient adjustment in both directions on the adjuster screws it doesn't matter which carb you start with.

[JWO261N]

I got a bit ‘creative’ this afternoon and went to my lockup to see if I still had a set of flat sides from back in the day.

Can’t find them

[JWO261N]

Yes! Those are Suzuki VM26.
No sign of the additional jet you mentioned..
The fuel mix screws underneath were set individually at the factory and sealed for US emissions.
There is no book setting.
Which Keyster kits did you fit and which components did you change.
Compared to the Z's VM's the pilots on these carbs are on the large side (usually 20 ) whilst the mains are smaller (around 95 compared to 112 ish ).
Apart from air screws and float valves you should re-fit all the original Mikuni internals if needles etc were changed.
Ideally you would use a Keyster GS1000 kit if absolutely necessary.
As for bench "syncing" the carbs.
The easiest way is to just set all the slides so that the cutaway is level with the top of the venturi bore when the throttle is open but make sure you are mid way travel on the screw adjusters and that the slides fully shut with the idle screw fully backed off.
Bench syncing only sets a baseline but doesn't ensure correct cylinder balance until vacuum adjusted.

Keyster kits are for A4 (from z-power) so just looks like I have the wrong kits for the carbs fitted. Duh!
One of the original needles looks bent to me.

I’ve bought a set of carbs from a known running A4 so they’ll be fitted this week. That should get me back to ground zero (ha!)

[chrisNI]

I’ll start looking for the factory manual, if I keep this bike I think I’ll need it ....

It can be hard to get them to run right they're not new bikes, and the person who sold you it obviously didn't before he let you have it. It's not rocket science, it'll be worth it in the end. Stick with it.

[JWO261N]

I’ll start looking for the factory manual, if I keep this bike I think I’ll need it ....

It can be hard to get them to run right they're not new bikes, and the person who sold you it obviously didn't before he let you have it. It's not rocket science, it'll be worth it in the end. Stick with it.

Cheers, problem is that the bike now feels like a noose round my neck