Question About FZ6's choke

[toybox]

Excuse me, does anyone happen to know at approximately what coolant temperature the FZ6's choke (or fast idle system) fully opens? I'd really appreciate any insights!

 

[TownsendsFJR1300]

On my '07, I'm guessing it'll idle down around 125F -130F...

That's with outside temps 60F plus..

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[toybox]

On my '07, I'm guessing it'll idle down around 125F -130F...

That's with outside temps 60F plus..

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Thank you so much for the information! I’ll be replacing the coolant temperature-controlled choke on my bike with an electronic one!

 

[Motogiro]

There is a coolant temperature connection to the throttle body assembly. This is controlled by input to the ECU from the air temperature and coolant temperature sensors.
I would imagine the control function of enrichment might be effected at the IAC valve as well as ECU control of the fuel inject during cold warm up.
The 2 sensors are thermistors.

 

[Gary in NJ]

toybox,

What year FZ6 do you have? Do you have an older aircooled model?

 

[toybox]

There is a coolant temperature connection to the throttle body assembly. This is controlled by input to the ECU from the air temperature and coolant temperature sensors.
I would imagine the control function of enrichment might be effected at the IAC valve as well as ECU control of the fuel inject during cold warm up.
The 2 sensors are thermistors.

My bike is a 2004 model, and its choke system isn’t connected to any electronic controls. So I’m planning to draw power for the electronic choke components separately from the main wiring. My idea is to install a temperature switch at the engine’s coolant outlet—once the coolant reaches a certain temperature and the switch closes the circuit, it will power the electronic choke, allowing it to heat up and gradually open the choke passage.

 

[toybox]

toybox,

What year FZ6 do you have? Do you have an older aircooled model?

My bike is a 2004 model, and it’s equipped with a liquid-cooling system.

 

[Motogiro]

My bike is a 2004 model, and its choke system isn’t connected to any electronic controls. So I’m planning to draw power for the electronic choke components separately from the main wiring. My idea is to install a temperature switch at the engine’s coolant outlet—once the coolant reaches a certain temperature and the switch closes the circuit, it will power the electronic choke, allowing it to heat up and gradually open the choke passage.

I'm confused. A 2004 FZ6 is the series 1 FZ6 Where is the choke? Are you talking about Idle Air Control? IAC?

 

[toybox]

I'm confused. A 2004 FZ6 is the series 1 FZ6 Where is the choke? Are you talking about Idle Air Control? IAC?

Yes, it’s the Idle Air Control (IAC), but I usually just call it the choke. I only use the term IAC when referring to fuel-injected models. That’s because those systems automatically control the idle based on temperature, whereas the early versions of the FZ6 didn’t have that feature.

 

[Motogiro]

Yes, it’s the Idle Air Control (IAC), but I usually just call it the choke. I only use the term IAC when referring to fuel-injected models. That’s because those systems automatically control the idle based on temperature, whereas the early versions of the FZ6 didn’t have that feature.

Wait... The 2004 FZ6 is fuel injection...No? There are no other earlier version of the FZ6 than the 2004. There is the FZ600 which was the earlier FZ model.

 

[toybox]

Wait... The 2004 FZ6 is fuel injection...No? There are no other earlier version of the FZ6 than the 2004. There is the FZ600 which was the earlier FZ model.

From what I understand…This is the IAC on the FZ6. It uses the engine's coolant passages to heat the choke, reducing airflow during a cold start. As the coolant temperature rises, the choke gradually opens to allow more air through. This system physically controls the choke based on temperature. In contrast, I believe a true IAC should be controlled by the ECU, using a motor to close off airflow before startup and then manage idle speed electronically as the engine warms up.

 

[Gary in NJ]

I think what is throwing everyone off is that you are calling the IAC a choke. A choke restricts airflow through the Venturi to force a rich mixture. If the FZ6 had a choke it would be installed in front of the throttle bodies. The IAC works allowing a closed loop map to keep a rich mixture until the throttle bodies reach a set temperature.

By the way…what problem are you trying to solve by modifying the IAC coolant circuit?

 

[toybox]

I think what is throwing everyone off is that you are calling the IAC a choke. A choke restricts airflow through the Venturi to force a rich mixture. If the FZ6 had a choke it would be installed in front of the throttle bodies. The IAC works allowing a closed loop map to keep a rich mixture until the throttle bodies reach a set temperature.

By the way…what problem are you trying to solve by modifying the IAC coolant circuit?

It might be a translation issue... The device you're referring to would typically be called a throttle body. But I’ve double-checked with GPT, and the term I’m using refers to the choke—one of the components commonly found on carbureted bikes.
The reason I'm modifying it is to reduce the amount of coolant piping, so the system can be tucked neatly inside the bike, giving it a cleaner external look. I also removed the rear seat cowl to expose the tubular frame, and relocated the fuse box and relay wiring into the storage compartment.
I’m aiming for a style similar to the Duke, since the FZ6’s frame isn’t symmetrical on both sides. I’ve also prepared a single-sided swingarm to replace the stock symmetrical one. On top of that, the offset position of the rear shock subtly supports this idea as well.

 

[tuning-forks]

I only use the term IAC when referring to fuel-injected models.

the term I’m using refers to the choke—one of the components commonly found on carbureted bikes.

Twice you have made it sound like your bike has carbs rather than fuel injection. I think the GPT translation is failing, or you have some other bike rather than the fuel injected FZ6.

 

[toybox]

Twice you have made it sound like your bike has carbs rather than fuel injection. I think the GPT translation is failing, or you have some other bike rather than the fuel injected FZ6.

I'm certain that I'm riding an FZ6, and its warm-up idle control is indeed managed automatically through coolant temperature. I've spent some time researching this system—it uses the flow of coolant to heat up a thermostatic wax (or temperature-sensitive wax), which in turn controls the opening and closing of the choke during engine warm-up. Maybe I should use gemini translation instead of chatgpt.

 

[Gary in NJ]

There is no wax inside that chamber, only a brass fitting. If you have wax....you have a problem.

 

[tuning-forks]

I think the wax refers to how the plunger in IAC is actuated. Same as in an automotive thermostat, thermostatic wax is used to expand and contract with temperature and actuate a plunger.
Including a link to a video about IAC operation, different Yamaha model but should be similar principles.

All this aside, I don't see how you can substitute electronic control. You would have to move to a stepper motor and re-design a new ECU.

IAC operation

 

[Gary in NJ]

Good video. It almost makes me want to remove the IAC from my spare engine and disassemble it.

 

[Motogiro]

I think the wax refers to how the plunger in IAC is actuated. Same as in an automotive thermostat, thermostatic wax is used to expand and contract with temperature and actuate a plunger.
Including a link to a video about IAC operation, different Yamaha model but should be similar principles.

All this aside, I don't see how you can substitute electronic control. You would have to move to a stepper motor and re-design a new ECU.

IAC operation

Very educational! Thank you!

 

[TownsendsFJR1300]

Re designing the wheel...

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