How to : Making a Throttle Return

**maybebuggy** · 12-31-2011 07:03 PM

Hi all, this is an answer or rather tutorial to the question of "how do I make the throttle bodies close with out using a dual cable set up". It is one way, it is not the only way, nor the best way perhaps, but it is a way.... I have a GSXR600 I assume this is applicable to any push pull dual cable throttle set up like the Zook has, I know the R6 is this way as well.

This is a prototype not a final piece, it is not super pretty I decided it would be a requirement to be made with off the shelf pieces and simple hand tools. Here is what I came up with, hopefully it helps someone!

I went to the hardware store (not hoe depot an actual hardware store) and got the following parts. You can see the stock GSXR600 throttle cables in plastic I got those on ebay for 12.00 shipped.

Item list:

1/2" aluminum tube
A spring that fits in the tube
A washer
A few 7/6" cable stops
A few smaller cable stops

First thing I did was to cut off the throttle body ends about a foot long worth of the OEM cables, I made one curved and one straight, you'll see in a bit. I wanted the metal cable routing elbows and a bit of cable.

Next I I measured the aluminum tube to spring length and cut it off with a pipe cutter.

Next I drilled out one of the 7/16 cable stops with a 6mm drill bit. Next I pressed the cable stop into the aluminum tube. I used a small bench vise.

Next I inserted the cut cable metal routing sheath, picture shows a straight section, you get that but cutting the elbow off. If you look above in hte olastic you can see the metal 30 degree or what not bend in the top right of the plastic.

In the other end of the aluminum tube, put the spring in the tube with the cable through the center of it. You can see it in the picture above as well.

By the way if the spring is a tad snug just ream it out with a rod and some emery cloth tacked to it with spray adhesive as shown below. I mention this since I have a few tubes actually that are the same and the spring slips inn with minimal friction on one tube and is a tad too snug on another tube. Of course the spring will wear in quickly anyhow just though I would mention it is all.

Then press the metal cable touring sheath in the 6mm drilled cable stop that you pressed in. It goes in with manual force almost o slop t0 speak of, 6mm is just right. Again it shows the straight one.

Next measure out the exact cable size you need. On the spring end run the cut cable end through a washer and then take a small cable stop and feed the cable through it.

In the picture you can see the washer which will act as a spring seat and the small cable stop right under my fingers.

If the washer is a tad too big just take it down a bit by clamping it in a nut a bolt and put a file to it. Pretty basic I know but I thought I would mention it anyhow. No need to hunt for the perfect size. By the way, the washer needs to small enough to fit in the tube and large enough to be wider than the spring diameter. It is basically a spring seat.

Once you get it sized cut the cable a bit and then double back the end of the cable through the small cable stop on top of the washer. I had to drill out the small cable stop a bit to accommodate 2 lengths of cable. Drill it out beg enough for 2 cable widths but not much more. What you will have a a cable going up through the stop then the cable doing a sharp 180 back down through the same way it came through the same hole. The result is a bulge on top of the cable stop. Pull it tight watching your length and then stick it in a vise and crush it closed.

Next, press in another 7/16 cable stop at the other end and run a machine screw through the end to give it a finished look and to seal it. Did not even need to tap it, just drilled it a tad wider is all. Fine threads cut through aluminum just fine. Use a longer end bolt and you can add pre-load and tension or make the cable longer by tightening it down into the tube pushing on top of the cable stop with the loop and compressing the spring.

By the way the cable stop that I used for the end cap has to be subtracted from the required length since pressing that in will pre-load the spring thereby pushing the cable down making it that much longer.

Here is a finished one that is curved, all I did was to not cut the metal cable routing sheath I left it full length. Doing so means it will follow the stock lines and not get in the way of the air box and what not.

Here it is installed. You can use a cable clamp and a small straight section if metal to bolt the cable clamp to the cable adjuster plate or you can use safety wire or any number of things to keep the curved version from swiveling if you want. The straight version sticks up or at the angle of the mounting plate I should say. You can see it 4 pictures up.

You now have a sealed throttle return spring that follows factory lines, is adjustable using the stock adjustment plus another one at the end if you opt to use a longer end bolt.

Simple how to for a 30 minute build with every part bought from an Ace hardware store and done using simple hand tools. It cost me $12 for the parts and $23 including the cables which I needed anyhow to size the ends and what not to have new cables made.

Easy to maintain or replace and you can even carry a spare with you, super convenient. Ohh, it snaps back with authority too!

A bit better than "use a return spring" for instructions huh?

Hope it helps someone! Best of luck!