Hello everyone.
Today's post is about lubricating my motorcycle's throttle cable.
Some recent bikes use electronic throttles, called 'throttle-by-wire' or 'ride-by-wire', with no cable at all.
Even so, I think most bikes still use a cable running from the twistgrip in your right hand.
If that cable snapped mid-tour, the bike would be undriveable and the trip would be over. You'd be calling a recovery truck.
To avoid that, the cable needs regular inspection and maintenance.
Ideally you'd inspect the cable for fraying or broken strands, but it's hidden inside its outer sleeve, so you can't see it.
That's why I think lubricating it is the best maintenance you can do to prevent a snapped cable.
Here I'll show how I lubricated the cable, using my BMW G650GS as the example.
The clutch cable needs lubricating in the same way. I've covered that in this post:
The photo above shows the throttle area of the G650GS.
A metal pipe rises from the base of the twistgrip, bends through 90 degrees, and then the black cable sleeve runs off to the right of the photo.
That's the throttle cable (the inner cable runs inside the metal pipe and the black sleeve).
The inner cable moves every time you open and close the throttle, so you can imagine it rubbing, especially at the 90-degree bend in the photo above.
Let's get it apart.
Or rather, before that, you need to record where the throttle housing was clamped, so you can put it back the same way.
Here, I note where the joint of the throttle housing lines up with the kill switch.
(Marking it with masking tape would be clearer and easier to reproduce.)
There should be a bolt near the base of the twistgrip that lets you take it apart; remove it.
On this bike it was a 4 mm hex bolt.
The housing at the base of the twistgrip comes apart in two halves; in the photo above, the lower half is off.
Sorry for jumping straight to it already apart, but this is the cable removed from the twistgrip.
The end of the cable has what's called a nipple (I think that's the term).
The nipple is what lets the twistgrip pull the cable. In other words, every bit of force that pulls the cable when you twist the throttle goes through the nipple.
Now, on with the job.
Under the black rubber boot is the mechanism for adjusting throttle free play.
To help the rubber slide, apply silicone grease or similar, then slide the boot back.
Sorry it's out of focus, but this is with the boot slid back.
Loosen the free play adjuster nut with an 8 mm spanner.
With the nut off, the throttle cable comes out.
Oil goes in at the two places marked with yellow arrows in the photo above.
For oiling, I use an AZ precision oiler (15 ml DX, soft needle nozzle type).
I also use this oiler for my chain; the nozzle can be bent, and a screw at its base lets you adjust the flow, which is handy.
One thing to watch out for here.
If you pour oil in, it will of course come out somewhere.
Unless you put a rag at the outlet beforehand, oil will end up on the bike.
The throttle cable connects to the throttle body near the engine, so that's where the oil comes out.
On the G650GS, the oil comes out where the yellow arrow is in the photo above.
(The photo is with the side panels and so on removed.)
This is the oil coming out of the outlet...
Horribly coloured oil came out.
As you can see from taking it apart, the twistgrip end of the throttle cable is designed so dirt has a hard time getting in.
That means this dirt probably got in from the throttle body end.
As you can see in the photo above, the part where the cable comes out is completely exposed.
Keep oiling until clean oil comes out.
Once the oiling is done, reassemble everything.
Grease the nipple (the end of the throttle cable) and any part of the cable you couldn't oil.
Once it's greased, put the throttle housing back in its original position.
As for the angle (position) at which to clamp the throttle housing, as I wrote at the start, use your mark as a guide.
I wrote earlier that you should check the position before taking it apart, but in reality I took it apart without checking.
So I decided to fit the throttle housing with its drain hole (in the photo above) facing straight down.
Once the throttle housing is clamped, adjust the throttle cable free play.
Finally, refit the protective rubber boot over the adjuster, and the job is done.
When I twisted the throttle, it felt lighter.
I think this should take a little of the fatigue out of long rides.