Quick question- do both carb and fuel injected bikes have off-throttle fuel shut off?

[racefactory]

Do fuel injected bikes and carb bikes both totally shut off fuel when the vehicle is in gear and engine is decelerating above idle rpm (DFCO)?

Cars do this and just wondering if a bike is any different. Don't see why it should be, just confirming.

What mechanism in a carburetor can perform this action and how?

Not what I'm asking for but I remember a ZXR250 I once had that the rpm decelerated rather slowly and wondered how this might fit in with DFCO.

[Max Preload]

Do fuel injected bikes and carb bikes both totally shut off fuel when the vehicle is in gear and engine is decelerating above idle rpm (DFCO)?

Cars do this and just wondering if a bike is any different. Don't see why it should be, just confirming.

What mechanism in a carburetor can perform this action and how?

Not what I'm asking for but I remember a ZXR250 I once had that the rpm decelerated rather slowly and wondered how this might fit in with DFCO.Never seen it on a carburettored bike. Or car that I can think of at this time of night.

Some carbs have an idle fuel shutoff solenoid to prevent run-on but I doubt it's implimented in that manner too.

Bear in mind most injected bikes have only become closed loop in fairly recent years while many cars have been for 2 decades.

[ducatilover]

One reason to keep a bike on it's idle circuit off the throttle is to help with throttle response once you get back on, in a way it's like an accelerator pump on a Holley. It also cools the intake valves.
As Max has said there are several fuel shut off systems, but, often these can be troublesome.

[imdying]

DFCO is currently too slow for a bike. It'll come though.

[racefactory]

thanks guys

[TripleZee Dyno]

Do fuel injected bikes and carb bikes both totally shut off fuel when the vehicle is in gear and engine is decelerating above idle rpm (DFCO)?

Cars do this and just wondering if a bike is any different. Don't see why it should be, just confirming.

What mechanism in a carburetor can perform this action and how?

Not what I'm asking for but I remember a ZXR250 I once had that the rpm decelerated rather slowly and wondered how this might fit in with DFCO.

Some carbs have vacuum operated bypass circuits which dump air or fuel (depending what problem they are trying to solve) into the idle circuit on a closed throttle/ high rpm.
A lot of the ecu we work on have tables for accel and decel enrichment/enleanment which we can adjust. 0-100%. Some are gear related but generally speaking the majority arent.
Another way to cut fuel is to zero the fuel map out in the areas you are interested in.

[BMWST?]

my k100rs of 8x vintage had fuel shutoff on overrun above about 1500 rpm(might have been higher rpm than that)

[racefactory]

Some carbs have vacuum operated bypass circuits which dump air or fuel (depending what problem they are trying to solve) into the idle circuit on a closed throttle/ high rpm.
A lot of the ecu we work on have tables for accel and decel enrichment/enleanment which we can adjust. 0-100%. Some are gear related but generally speaking the majority arent.
Another way to cut fuel is to zero the fuel map out in the areas you are interested in.

So on stock sports bikes in your experience do they cut off on the closed throttle?

[racefactory]

So basically all sports bikes still run on idle circuit when off the throttle? Fuel doesn't stop injecting?

Carburettor bikes?

[scumdog]

So basically all sports bikes still run on idle circuit when off the throttle? Fuel doesn't stop injecting?

Carburettor bikes?

Carb bikes from my experience don't have less-than-idle fuel going into them, i.e. pull in the clutch and the motor will be running at the revs it doeas at idle (give or take a little)

If all fuel was cut off there would be a bog when you cranked on the throttle again.

[ducatilover]

If all fuel was cut off there would be a bog when you cranked on the throttle again.

This is true, hence the Holley accelerator pump for when you stab the gas :devil2:

[HQfiend]

If all fuel was cut off there would be a bog when you cranked on the throttle again.

If all fuel was cut off engine would stop

[scumdog]

If all fuel was cut off engine would stop

It would still turn over as if there was still fuel available if the car was in gear and moving, it would not behave that differently at all. Until you opened the throttle..:blink::eek5:

[DEATH_INC.]

It would still turn over as if there was still fuel available if the car was in gear and moving, it would not behave that differently at all. Until you opened the throttle..:blink::eek5:
Yup, most efi systems do this, it's what you feel as a slight stumble as you try to gently roll the gas back on mid-corner. It's an economy / emissions thing too.
Carbs generally don't....bikes anyhoo, though I've never seen it on a car either.
The accelerator pump is for a very different reason.
Look up piccys of an 06/07 ZX10r racebike, or The R1's with underseat exhausts and race ecu's, and see what happens when you remove this feature.