One or two Throttle Cables?

Q. has anyone removed the push part of their throttle cable, or must it be left on. mine seemed to be a bit stiff and return a bit slow and the cables are fine, I removed the push cable and it pulls a lot quicker and springs back a lot better. What do the rest of you run??

A. I am of the “OPINION”, that it is perfectly OKAY to use just the opening cable on CV Constant Velocity carbs, BUT NOT FLATSLIDES, maybe!

Here’s why, on CV carbs the throttle butterfly will snap closed when the throttle is released because the airflow through the carbs will push the butterfly closed, kind of like a strong wind blowing a door closed. Once the butterfly closes, the vacuum slides have no choice but to DROP SHUT!

For many years manufacturers only used one cable on CV carbs. I remember having one cable on my 84 Zx 750 turbo. Never was no problem there even under high boost conditions.

Flatslides are another story. High velocity through the carbs could prevent the slides from coming down on their own, hence the reason manufacturers put such strong springs on them.

However in 1992, when we updated from a CV equipped 89ZX7 race bike to a flatslide equipped 92ZXR, my rider complained about how far he had to turn the throttle to wide open. On the 89, we were running a 1/8th turn throttle made by “MAGURA”. This twistgrip had a metal housing an a 2 step adjustment, one was for motocross and the other was for supercross?. This was dirtbike throttle. You may hear the term 1/4 turn or quick turn throttle. Actually most bikes are already 1/4 turn and what they are talking about was 1/8 turn. So we moved this throttle from the 89 onto the 92R and used it for several months with nary a problem. However this was dangerous! I later used this on my street bike and boy once you get used to it, you never want to go back, but it is dangerous.

You are looking at problems on CV carbs if something come loose or get stuck, but in that case how are you going to benefit from a close cable?

I am of the opinion that removing the close cable on a CV carb is totally safe, and will reduce a good deal of friction and would do it if I had one!

But just my opinion, and welcome others to it!

Ken H2Os

next post By Gary D.
I found similar troubles on my 92 R. What I found was that when the return cable was in what seemed to be the proper adjustment hole (excuse my terminology), it stuck. I loosened it one hole and gave it a bit of slack and it snaps back no problem.

This site is kindly funded by the politically correct folks at redmonkey.org

They are very helpful as long as you fill in your profile – your favourite dish had better be roasted nuts if you fail to adhere to this one and only site rule!