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Discussion Starter · #1 ·
While reading about the description and operation for the carbs on my 350 k4, i came up with a few questions
1. Is there a leaner A/F ratio at low speeds, and a stoich-richer A/F ratio at mid-high speeds - being that there are two fuel circuits per one air circuit.

2. If larger jets are installed in the carbs to accomodate a more free flowing exhaust, should the float height be raised(or lowered?) to allow a greater amount of fuel into the float bowl?

Reading about the carbs on my 350k4. pretty cool technology.
Thanks
-dan
 

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Dan, to give a simple answer to your question - no.
Because the airspeed through the carb is relatively slow at idle, the secondary/ idle circuit is used.
As the air speed increases it can pull fuel through the main jet assembly.
The float chamber is only there to create a stable reservoir for the two circuits to work from, the float height keeps that reservoir at the optimum level.
Hope that makes sense.
 

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Sensei
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.....They are CV carbs....That means the air VELOCITY remains constant.....
The amount of fuel delivered is dependant on the Volume of air (actually, the mass of that volume) and the relative opening of the needle jet (changes with how much the tapered needle is withdrawn by the lifting slide...... The main jets controls the maximum flow rate/fuel volume available to the base of the needle jet .....
The idle jet and mixture screw are parts of a separate fuel circuit, and an be set leaner or richer according to the engines needs......
The float bowl/float height information is essentially correct.......
 

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Man I love fuel injection.

Ok so this may be taking the thread off course a touch so feel free to delete or move if needed. On the topic of CV carb function I understand the air box and particularly the volume of the air box is pretty critical to the proper function. So how are the cafe and bobber guys dealing with no airbox? Are they jetting around the problem or simply dealing with a poorly tuned bike? Velocity stacks have any positive or negative effects on CV carbs?
 

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Discussion Starter · #5 ·
Thank you gentlemen for the info replys.
-Dan
btw i finally got my 350 on the road.
 
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