Throttle Return Spring

I have been doing some research for the past week or so concerning the stock Keihin return spring. This year while racing the GNCC Series (2.5 to 3 hours per race) The throttle pull almost became unbearable when arm pump set in. I have been trying to fine someone that makes a spring with a much lighter pull for better response. So far no luck. Below is the response I recieved from the manufacturer.

What I'm basically looking for is a throttle that snaps just by thinking about it. This past week I changed from a Plastic Throttle tube to an Aluminium (Works Connection) in hopes that some of the friction will disappear.

Anybody else got any ideas?



I have forwarded your request to an engineer familiar with the productline.

The information I received is that due to safety issues, Keihin does not offer or recommend throttle return springs with pulls lighter than the original spring. Also, any other spare parts/replacement issues are handled directly by

our distributors.

SUDCO 800.998.3529

DG 800.854.8052

Hope this information helps.

Bonzai :)

Do you put any grease in between the throttle tube and the handlebars?

Rich, if Bonzai used any grease he would have to add Throttle Grease to his signature line :D:)

Good one!


I recognize that! another attempt at humor....Keep trying you'll get there.

Bonzai :)


Have you thought of running with just one cable? This will reduce drag on opening and closing throttle.

OK, there is a risk of throttle sticking WFO but whats the real chance of that happening - I think none.

Plus you save all that weight!


i seen a lot of harleys with a little throttle attachment that works like cruise control.that way they can ran with no hands.the sell it at sure it can be modified to work on your bike.but it definetly not legal in ama sanctioned event.come to think of it what is legal in a ama event?

From what i have been told the 4-bangers have 2-throttle cabels and a heavy return spring because of vacume. The slide could hold open when you let off the throttle. Its just what i have heard and dont know if it true. anybody else?


go to swapmeet and buy a set of "ape hangers"with cruise control i think 57'rigid or any bars off fatboy with fit yz426's.


Interesting - I get the idea, but how could the engine generate a vacuum with the slide open? I would have thought the effect of vacuum would be felt when trying to open the throttle while under engine braking?


[ June 16, 2002: Message edited by: wrsm ]

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