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Not ALL CV carbs need a velocity stack. Most, maybe.
Show me one that doesn't need a velocity stack. If he looks at the parts he took off that motorcycle, it will include the stacks and that would be a darn good indication they are needed.
... maybe those pods have stacks inside them but I seriously doubt it and that would account for his need for additional tweaking .

Did you see his crankcase vent, how long will that work before it is saturated with oil and starts spewing black mung all over the back of the engine?
 

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1982 Yamaha XJ650/1981 Honda CB650
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my issue is going from idle to mid range the engine stumbles some. Top end it screams rpms. velocity stacks look sweat but prefer pods for air intake quality, ingesting dust and gravel would be bad for the engine, velocity stacks have none to minimal filtering. i increased my pilot jet slightly, added a shim under the needles and adjusted the air/fuel mixture screw. still stumbles before it goes from idle to mid.
 

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my issue is going from idle to mid range the engine stumbles some. Top end it screams rpms. velocity stacks look sweat but prefer pods for air intake quality, ingesting dust and gravel would be bad for the engine, velocity stacks have none to minimal filtering. i increased my pilot jet slightly, added a shim under the needles and adjusted the air/fuel mixture screw. still stumbles before it goes from idle to mid.
Yep, it's called flat spots. Put some stacks on it and it will tune.
Velocity stack has nothing to do with air filtration, that's a different part, the manufacturer did not put them on there for looks or because they wanted to increase the production cost, they were on there because they are necessary.
 

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my issue is going from idle to mid range the engine stumbles some. Top end it screams rpms. velocity stacks look sweat but prefer pods for air intake quality, ingesting dust and gravel would be bad for the engine, velocity stacks have none to minimal filtering. i increased my pilot jet slightly, added a shim under the needles and adjusted the air/fuel mixture screw. still stumbles before it goes from idle to mid.
When we are talking velocity stacks, it's not the open stacks seen on some carbs like you mentioned - it's an extension from the carb to the intake, like a long intake manifold....at least that's my understanding of the term.
 

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Ok now i understand wat velocity stacks are, yep they were the black inlets between carb and airbox. sorry
Put them back on and your tuning problem will go away.

4-stroke piston reciprocating engines All have piston blow-by and the crankcase is vented to atmosphere so water ends up in there too. The crankcase vent needs to vent somewhere and the airbox was designed to collect the mung that comes out of that vent. You need something that does all that and does not end up restricting air movement ever, because the crankcase needs to remain at atmospheric pressure.


:cool: going riding on my go fast motorcycle now, it has stacks too (y)
 
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