Throttle Cables

[Rednaxs60]

While I was doing my side stand interlock/indicator light project, I decided to address an issue that was found last year during a track day. The facilitators at the track did a short safety survey of each bike to ensure that you were safe to be on the track. My issue was that the throttle did not return as fast it should. I worked on it and was finally allowed to participate, but have had this in the back of my mind to fix.

When I took the switches off to do the side stand mod, I decided to replace the throttle cables. The two cables I wanted to replace were the push and pull cables. The pull cable goes to the throttle linkage at the back of the engine. The push cable goes to the cruise control connection under the faux tank.

I ordered in new cables but only one was a fit, for the pull cable. I also decided to replace the throttle tube as well. My '85 is the fuel injected model so I had to remove the fuel filter:

CFI Covers:

Remove the throttle tube and hand warmer:

Remove the hand warmer from the old throttle tube:

I replaced the throttle tube because I thought one of the cable grommet holes was enlarged.

The throttle tube cable hole(s) are designed with one as an exact fit and the other elongated. Since I had the new one, I cleaned and installed it.

Next Post.

[Rednaxs60]

The cable I ended up replacing that goes to the throttle linkage at the back of the engine was the culprit that was making the throttle "stick". You can see in this picture where there is an almost 90 degree kink in the old cable.

I'm surmising that the cable has cut into the internal sheath and was binding causing the throttle to not return as it should have. I was going to cut the old cable open to view the inside but have since discarded it - would have been good to see.

I was further reminded that work space on these bikes is very limited. One of my very best friends for a job like this was my 11 inch long needle nose pliers:

Highly recommended as a purchase.

Cheers

[WingAdmin]

It should be mentioned that throttle cable routing can be critical. Assuming the existing routing is correct (and hasn't been messed up by a previous owner), the best way to ensure that the cables are routed properly is to tape or otherwise fasten the throttle end of one cable to the grip end of the other (or vice versa), then use the old cable to pull the new cable into place. This ensures the new cable threads its way into place in the exact same way as the old one was installed.

In the case with the 45 degree cable, I suspect this cable might have been routed incorrectly, and had gotten pinched somewhere.

[rmateer]

wing Admin. I followed your pictorial of the 1100 to the T !! the part where you said to twist the to halves on the handlebars until it finds the right spot I did. The problem I'm having is when you open the throttle there is no return!! If I move the two halves towards the end of the handlebar an inch or two it works fine?? Both adjusters are fully closed. Should I try to adjust them with the two halves in the right position?? Got any ideas?? I looked at my other bikes and I don't see anything different!! By the way I have 3 1984 GL1200A Aspencades that are identical!! Same color, same everything except the VIN numbers!! It really confuses the county treasure when I get them Licensed!! Don't have to do that anymore they are all antiques!! I don't have to ever license them again!!!

[WingAdmin]

wing Admin. I followed your pictorial of the 1100 to the T !! the part where you said to twist the to halves on the handlebars until it finds the right spot I did. The problem I'm having is when you open the throttle there is no return!! If I move the two halves towards the end of the handlebar an inch or two it works fine?? Both adjusters are fully closed. Should I try to adjust them with the two halves in the right position?? Got any ideas?? I looked at my other bikes and I don't see anything different!! By the way I have 3 1984 GL1200A Aspencades that are identical!! Same color, same everything except the VIN numbers!! It really confuses the county treasure when I get them Licensed!! Don't have to do that anymore they are all antiques!! I don't have to ever license them again!!!

There are normally three causes for the throttle to not snap closed when you let go:

- Weak throttle return spring. This happens over time, and it's pretty much a given now that our older bikes don't have as strong springs as they used to.
- Too sharp a radius somewhere in one of the cables. This is usually caused by a cable not routed properly (and is why it's so important that they are)
- Throttle cable tension adjusted too tight. There should be a small amount of play (it differs by model), but there must be some, otherwise the cables bind up and the spring can't overcome the friction. If you loosen off the tension and it fixes the problem, then this is likely what's going on.