Vm28ss vs 28sc ?!

Hello guys, I finally have find a set of Kz1000 Carbs for my kz750.. it measure 28.5mm so I know thats 4 Mikuni VM28.. the guys say that they don’t have a accelerator pump.. what kind of VM you think they are?!  He doesn’t know what year exactly the carbs are from.  How can I identify them, and whats the pros and cons of these 2 kind (ss or sc)!! 

Aren't the SC version the early type, as fit to Z1's?  

 

VMSS carbs will have a 3 bolt top chamber cap, SC will have a 2 bolt cap. SS will have one extension return spring, SC will have torsion spring/s around the throttle shaft. Early SC carbs will have a large float bowl nut, used to make main Jet changes easier, SS will have a small brass drain screw. It’s said that the SS will be more stable and hold a tune better. SS will be cheaper at about $300 for a good used set, SC about $500. Pictures will help.

Has anyone here run VM28's on a 750?  They seem way too big for a 738cc bike.

The SC carbs have two bolt tops and the SS carbs have 3 bolt tops so easy for the seller to confirm which they are if he can't provide a picture.
The SS are better with enclosed slide adjustment and don't easily wander out of sync like the SC's so hopefully they are what he has.


 

Thank youuu guys!! And does all  the vm has a accelerator pump ?!

I just call a gasket kit on ebay for the carbs.. I tried to find Needle float too, but  cannot find one!!? Do you think I need to change them before to go on the dyno?  

Not all VM28's have pumps.
It depends on which model and year the carbs are from.
Also i would not be buying anything until you have the carbs in hand to ensure you only buy parts that are correct and needed.

The only VM28SS carbs without a pump that I know of were used on the '78 Z1R.  The big Suzukis may have also used 28 non pumpers but I have no knowledge of the Suzukis other than they usually had both air/fuel screws AND pilot adjusters.

I support Nessism's concern that 28's are too big to be used on a 750 engine.

They will be too big for my 750?  Even with pods, milled head, mild porting and 0.5 oversize?!

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They will be too big for my 750?  Even with pods, milled head, mild porting and 0.5 oversize?!

No!  Set up correctly they will be fine.
 

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The only VM28SS carbs without a pump that I know of were used on the '78 Z1R.  The big Suzukis may have also used 28 non pumpers but I have no knowledge of the Suzukis other than they usually had both air/fuel screws AND pilot adjusters.



 

Yes ! Non of the  VM26 or VM28 Mikunis fitted to the GS's as stock ( including the VM32's as fitted to the GSX1000S Katana) ever had accelerator pumps and all had both fuel and air screws present.
As for the pumper 28's on KZ's.
This only applies mostly to US equipped machines to help comply with the emmisions laws..
Other countries didn't have the strict emmisions laws to contend with so didn't get pumpers on any KZ model that was originally destined for their market.