Sticky Throttle

[TheCaptain]

My bike appears to have developed a problem which makes me feel like I'm going to crash at any moment.

When applying the throttle, it has a tendency to stick. So as opposed to it idling at 1400rpm, the stuck throttle raises it to 3000rpm.

I believe what's happened is either the throttle cable is stuck somewhere, or it's just really dry. The problem is I just had a look at the throttle cable and am not sure how to go about lubing it. Has anyone else had this problem? And are there any suggestions to rectify the problem?

Thanks

[Red Herring]

Hello mate, that's quite a high ticker even at 1,400, should be a tad less than that. I'm guessing it's an SV, is it a Curvy with carbs, or a Pointy with Fi?

[TheCaptain]

1400 was just an estimate, it's more like 1250-1300rpm. It is the EFI Pointy.
I know the throttle is sticking, so I don't think there's something wrong with the EFI. If I sort out the throttle cable and the problem persists, I'll know it's the EFI and I'll take it to a dealer.

[Stuart42]

Hi

Also check the throttle grip isn't sticking on the bar end weight, as had similar on mine.

Cheers
Stuart

[TheCaptain]

It's not that, my bar end fell off on the M4 a couple of months ago, so that's gone.

[Red Herring]

The Pointy has a twin throttle cable arrangement so it doesn't rely on a spring to close the throttle (there is one as well). There is a cable that pulls it shut therefore if you close the throttle by hand then it should return to the stop. Poorly lubricated cables may make the throttle action heavy or "stiff" but you should still be able to return the engine to tick over.

If your tick over had gone haywire even when the throttle is properly shut then you may need to check the throttle bodies are balanced (in synch) of if it has always been that way just turn it down a bit (screw on left side just behind the frame cross piece).

[Red Herring]

By the way if you want to lubricate the throttle cables then take out the two cross head screws holding the right handlebar switchgear/twist grip (underneath) and you should be able to separate them. You can then take out the ends of the cables. Wedge then with something so that they both point up in the air and then slowly drip a really light oil like GT85. WD40 or similar on the exposed centre of each cable and it will slowly run down inside the sheath. (You can buy a little adaptor that clamps around the cable allowing you to fire it in under pressure but I'm guessing you don't have one of these). If you work the cables a bit it can speed things up but basically you just need to be patient and leave it 10-20 minutes between applications. Whilst you have it apart slip the throttle tube off the end of the handlebar and make sure that is nice and clean. You can put some light oil on it if you want but don't be tempted to use grease, that just results in a sticky mess that traps grit.
Once the cables are moving nice and freely just put it all back together again.

[Sid Squid]

Like RH says, there are two cables one which closes the throttle when you roll the grip forwards. If doing so brings the throttle shut against firm resistance, but does not bring the engine speed down, then the fault is not with the cables. As you have a Pointy I would first look at the secondary throttle actuator system, as this controls the 'choke' idle.

[wideguy]

Also possible that the mechanism at the throttle bodies is very dirty. Happened to me once on my carbs. I complained to my mechanic (me), and then cleaned everything off, which solved my problem.

[andy1472]

WD40 is too thin to use as a lubricant as it's a freeing/penetrating agent and will eventually run through the cable with the forward and backwards motion of the inner cable. (thick oil will stay in there and not only lubricate but prevent water getting in).
Right now I have a 'close' throttle cable on my newest bike that has never been lubed. It's snapped in half inside the outer sheath...I'll post pics when I get it off.


The best method and you only need to do this every two years to make your cables last years is as follows;
Remove the cables from the bike completely and you may as well do the clutch cable too as your routine maintenance (nothing worse than a broke clutch cable 200 miles from home). Cable tie a small plastic bag round the bottom on each cable to catch the drips. Suspend the cable vertically with twine or whatever you have and cable tie another bag on each top end too (around 2" to 3" below the cable end and you need to suspend this bag upright too to stop it flopping down when you put oil in it - just tie it to the twine your using to suspend the cable) and pour in some decent engine oil and leave overnight. By the morning the oil will have seeped it's way through the cable and left a nice thick lubricating layer inside coating the steel wire.
Replace back on the bike and forget about it for two years. Repeat as part of your home service and save £20 a cable.


Alternatively instead of tying a bag round the top you can make a bowl/dish shape out or plasticine, trap the cable in the middle of it and pour the oil in there. Whatever you have in the house.


Penetrating oil is too thin. Trust me, I'm a tool maker. I know about oil.


Thanks.


[edited a few typos]

[Red Herring]

Penetrating oil is to thin to act as a long term lubricating oil yes, but it's excellent for getting down a stiff unlubricated cable in order to free it off. You can then put some heavier lubricating oil down. As you say though, best to stop it getting to the point where you need the penetrating oil in the first place.

[johnnyrod]

Kinked cable? They stick quite badly