Vb42 vs vb43

[sdew99]

Just acquired a set of vb43 keihin carbs.. look like they were from the 900s? Anyone know what the differences are between the vb42 and vb43?
Compatible with a 750?
Tia

 

[Loose Chain]

Some cb900's used the same size carbs as the CB750. You will have to measure the diameter on the filter side and intake side and compare them. The VB43's might be larger. This below will give you the internal sizes but it doesn't give the in and out diameters.

https://motorcycleproject.com/text/specs.html

 

[Loose Chain]

3-Jet Vacuum Slide EPA Spec​

o Hidden Emulsion Type Idle Mixture Screw o Non-Replaceable Slow Speed Jet, Some Models o Non-Adjustable Jet Needle, All Models o Air Cut Valves, All Models o Twin Sequentially Functioning Main Jets o Accelerator Pump, All Models

750 79-82 900 80-82 1000 (83) CBX (79)​

 

[sdew99]

Some cb900's used the same size carbs as the CB750. You will have to measure the diameter on the filter side and intake side and compare them. The VB43's might be larger. This below will give you the internal sizes but it doesn't give the in and out diameters.

https://motorcycleproject.com/text/specs.html

Looks like the slow jet is 38 instead of 35. Darn.

 

[Loose Chain]

That doesn't matter. Your 750 would probably like it. I run 38's in mine and the 105's

 

[brettp]

The slow jet is based on the carb's air flow to achieve a fuel/air mix of ~1:17 (I think). It isn't about the engine.

 

[Loose Chain]

If you plan to run the 900 carbs just use the jets out of your 750 carbs if you don't like the idea of larger jets.