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I love my wife!
Blue ‘02
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Discussion Starter · #1 ·
After sitting for a year or more, my ‘02 R1 was revving higher and higher after starting, up to about 4k or so (and of course then overheating). I checked and/or replacing everything I could find in the factory shop manual, including rebuilding the water pump, replacing the radiator, etc. No luck.

Then in a whim I took this thing apart, found it frozen stuck, cleaned and lubed it, reinstalled it, and voila, problem solved, for free.

It’s sort of part of the throttle body, attached to it, under the left rear part of the tank. But I cannot find it listed in the manual, though the picture is there, and it’s also pictured but not labeled or numbered on the online factory parts diagrams. It’s a phantom part.

WHAT IS THIS THING?????🤣
1019950


1019949
 

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'08 r1
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Looks like it might be a knuter valve. I was thinking it looked like an air injector solenoid for the pairs, but I think I've settled on knuter valve.

Why don't they ever show the knuter valve in the manual? I spent 20 minutes looking at the standard us model and the California model to see if I could find it and I couldn't. So I am going to say knuter valve again.
 

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An R1 kinda day!
2015 Yamaha YZF R1 Raven Edition
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Cold start valve?
 
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I love my wife!
Blue ‘02
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778 Posts
Discussion Starter · #6 ·
Cold start valve?
Yeah I would say that HAS to be what it is according to what I experienced with it. But it’s like Yamaha all but denies its existence. I have no idea how you would even go about buying a new one if it doesn’t have a part number or official name. (I don’t need a new one, just saying it would suck if I did!)
 

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Yeah I would say that HAS to be what it is according to what I experienced with it. But it’s like Yamaha all but denies its existence. I have no idea how you would even go about buying a new one if it doesn’t have a part number or official name. (I don’t need a new one, just saying it would suck if I did!)
If the knuter valve ever goes out, you have to buy another machine.

:fact
 

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An R1 kinda day!
2015 Yamaha YZF R1 Raven Edition
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My cat's been knutered.
 
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2016 YZF-R1
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That is the fast idle actuator. It is a temperature controlled plunger that raises the engine idle speed as the machine warms up. Coolant flows through the plunger body to provide the engine temperature.
 

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That is the fast idle actuator. It is a temperature controlled plunger that raises the engine idle speed as the machine warms up. Coolant flows through the plunger body to provide the engine temperature.
So it's an electronic enrichener like jsp said. Good deal. I guess it isn't a knuter valve.
 

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I love my wife!
Blue ‘02
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778 Posts
Discussion Starter · #13 ·
That is the fast idle actuator. It is a temperature controlled plunger that raises the engine idle speed as the machine warms up. Coolant flows through the plunger body to provide the engine temperature.
Interesting. I assumed it was fuel in the lines, but coolant makes more sense. Thanks!

It being stuck fast in one position caused the bike to slowly raise the idle from 1k at first, when cold, to over 4k, within only a couple of minutes, until the coolant was boiling and I shut it off. (I even had to replace the coolant expansion tank on the side because it melted too much where it attaches to the radiator and was about to fall off.)

Since I freed that plunger, it's been purring like a kitten.

I still wonder why Yamaha seems to deny its existence though.

Thanks all!
 
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