Help With New Throttle Cable Install (Adjustment)

[toreckman]

I installed a new set of throttle cables, routed in stock location, so no kinks or rubbing etc.

 

The issue I have is the throttle doesn't snap back.

 

I adjusted the main cable at the handlebars by turning it in (as I understand this is adding more slack?) and this helped some but I have it adjusted to the max.

 

 

My understanding is I need to adjust it at the throttle body end to give me more adjustment at the handlebar end?  But for the life of me I cannot figure out how to do this.

 

 

Using nuts 1-3, how do I adjust the cable to give more slack?  Direction to turn nuts?

Will I need to remove the plate (held in by 2 screws) that holds them down again to do this?

Are 2 and 3 supposed to be tight against the plate cable guide?

Do I need to adjust the return cable (the bottom cable)?  If so, which direction?

 

Sorry for all the questions, I just cant figure it out how the throttle cable system works, particularly the directions of slackening and tightening.

[vfrgiving]

Major adjustments are done with the nuts at the throttle body end.  The adjusters up at the grip end are for fine adjustment.  Running the adjusters up top in adds slack as you are shortening the cable sheath exposing more cable.  Running the adjusters out to expose more thread lengthens the sheath and tightens slack on the cable.

[Terry]

From the photos, you already have as much slack as you can get as the TB adjusters and the grip adjusters are as short as the can go (the outer is as close to the drum as it can go). I'd be taking a look at the routing of the cables to make sure they follow the prescribed path. The General Info section of the service manual has the helpful pictures. You might also check that the throttle drum has been lubricated where it turns on the bar, and that the bar end is not clashing with the grip rubber and causing binding.

 

If you really get stuck, you could take nut 2 out of the equation and snug the big adjuster nut up against the bracket with just nut 3 as a locknut.

 

The big question is how much slack do you have at the twistgrip? You need a few mm of freeplay, but do you already have lots?

[toreckman]

Thanks for the replies.  I had another go at it today.

 

I forgot to mention this is part of an ABM straight bar conversion and the throttle cables are longer cables (they are designed for the VFR though) and there seems like definitely enough length.

 

The routing is stock and I removed the cable bracket today again as I thought the cables were wrapped around each other, but they are fine, not rubbing etc.  @Terry There is no slack at the twist grip.

 

 

 

If I pull the throttle slightly off the bar it works fine (but still no slack).

 

But when I put it back to the stock location it will not snap back at all:

 

Do these nuts on the bottom of the twist grip, allow any adjustment?  Or are they just for holding the cable guides in?

 

 

Does the return cable need adjusting at all, at the throttle body end?  Maybe its too loose?  It is slightly loose when I check it at the TB.

 

As a last resort I will have to try and remove that nut no.2 and see if it gives me enough slack.

[Terry]

The nuts under the throttle housing are just to orient the elbows, there's no adjustment to be had there.

 

Looks like no grease on the handlebar. Some silicone grease would be a big help to allowing the throttle tube to rotate freely. 

[toreckman]

3 minutes ago, Terry said:

 

Looks like no grease on the handlebar. Some silicone grease would be a big help to allowing the throttle tube to rotate freely. 

Do I grease the mechanism the cables attach to or do you mean the whole throttle tube?

 

I am still wondering why it works if I move the throttle further down the bar.  Wouldn't this be reducing slack?  Also means it isn't a lubrication issue?

[Captain 80s]

20 minutes ago, Terry said:

The nuts under the throttle housing are just to orient the elbows, there's no adjustment to be had there.

 

How far you thread in one of the cables into the housing before locking the nut definitely affects free-play, but it looks like he has it pretty far engaged.

 

Also the picture where you can see the actual inner cable and the housing is partially split open, was that just taken while you were still assembling?

 

Also are you sure you are getting the locating pin on the housing correctly engaged in the hole on the bar?

[toreckman]

11 minutes ago, Captain 80s said:

 

Also the picture where you can see the actual inner cable and the housing is partially split open, was just that taken while you were still assembling?

 

Also are you sure you are getting the locating pin correctly engaged in the hole in the bar?

Yes i tightened up the nuts today when I reinstalled the bracket.

 

There is no hole yet. The instructions say to do this last when you are happy everything is set up ok. I am holding the twistgrip housing tight while testing the throttle.  Also like i said if i move the throttle towards off the bar it works fine, albeit with no slack.

[Captain 80s]

I think that is part of your problem regarding return action while on the bar.  You can also try adding a couple revolutions on the cable that threads into the housing for some more slack (as long as there are threads left for the lock nut...   maybe not looking at it again) if you are confident that everything else is properly assembled.

 

One last caution before drilling your hole...   make sure you have the housing rotated far enough so the brake lever doesn't come into the cables when squeezed.

[toreckman]

I managed to get this sorted.  I rerouted the cables, but that didn't work.  So I routed them back again to stock and magically the throttle works fine now. 

Maybe it was snagging somewhere before.

There is only 1-2mm slack, but I have done extensive testing moving the bar left to right and it doesn't effect the rpm.  Throttle snaps back nicely every time.

[Captain 80s]

Good news