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Discussion Starter #1 (Edited)
Choke lever and gas consumption

I've been wondering why I never get 40 mpg on my ST2. I've got Ferracci pipes and chip, it was dynoed that way by the PO, running well but I haven't yet had it tuned so I don't know if it's out of spec or not. But I noticed something over the weekend when I was doing my fluids change.

When I put the choke lever on, it does 2 things - it rotates the choke cam up against a stop pin and in the process, moves the throttle position cam so that the idle speed goes up a bit. When I move the choke lever after I'm running and warmed up for a few seconds, the throttle cam gets released and the idle speed goes down - but the choke cam doesn't move all the way against the stop pin on the other side. Should it? I'm wondering if the cable is too tight and I never fully get the choke off.

I hope this makes sense - I've haven't made any attempts to adjust this bike yet, so I don't know what I'm talking about - and neither the parts manual nor the workshop manual makes it clear what's supposed to happen with the choke cam.
 

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Mr Leakered
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The fast idle should not open or touch the throttle when it is "off." The steering should be checked from lock to lock that the idle lever doesn't load the throttle and the RPMs don't change due to the throttle cable either.

Have a good one.
 

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It's not realy a choke at all its just a high idle setting so if it does not touch the throttle cam when you steer lock to lock its fine.

That is to say theres no choke flap / slide / needle etc inside the throttle bodys like in you Norton's
 

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Discussion Starter #4
So its only function is to kick up the idle by moving the big cam on the throttle body? If so, then it's set up just fine. Thanks - I thought it did something additional to that.
 

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So its only function is to kick up the idle by moving the big cam on the throttle body? If so, then it's set up just fine. Thanks - I thought it did something additional to that.
correct! just a idle kick up.
Some like to use it as a cruise control for when the right hand goes numb just be sure keep left thumb on it so you can shut it off quickly if need be.
 

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Discussion Starter #6
Then I'm doubly glad to know all this - it's way cheaper than a Throttlemeister...
 

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- but the choke cam doesn't move all the way against the stop pin on the other side. Should it?...
Yes, but if your are idling at 1200 rpms, you're okay. If higher you may want to relax the cable.
 

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Discussion Starter #8
Gotta look, but 1200 sounds about where it's at. It's not high.
I originally posted this because I'm not getting great gas mileage, and I wanted to make sure that it wasn't a real choke lever - didn't want to be running rich all the time because of a tight cable. Now that I know how it works, I know that IT AIN'T THAT....
 

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Mine is set so I only need to slide it in line with the hi beam button to start the bike but can set for 3900 rpm going down the road. BEWARE that unlike a thottlemisser you can't just twist the throttle back to idle if you use it as a cruise control you have to move the slide.

This dosn't bother me at all as my 52 harley has no return spring so i'm use to "dead man's" throttle.
 

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Gotta look, but 1200 sounds about where it's at. It's not high.
I originally posted this because I'm not getting great gas mileage, and I wanted to make sure that it wasn't a real choke lever - didn't want to be running rich all the time because of a tight cable. Now that I know how it works, I know that IT AIN'T THAT....
Maybe a water temp sensor is on the way out? Maybe it reads colder than it is causing the ecu to enrich longer than it needs to? :think:
 

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Discussion Starter #11
Thanks! - that's worth a try. I've replaced the one for the read-out with a NAPA sensor, but not the one that feeds the ECU. That's gotta be worth the experiment.
 
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