Hi All
I have a stiff throttle, is anyone else suffering from this condition?
I have taken the twist grip to pieces and cleaned the twist grip and the little chain linkage, all seems free, it was full of mucky old grease but is now spotless and lightly lubricated. I have pulled the cable to the carbs with some pliers this seems free enough although hardish to pull, is there a strong spring at the other end that is adjustable or do I need to do some extra wrist exercises!
One other thing, when I took the twist grip to bits there are two wires inside the handle bar, obviously this is for the heated grips the right one is not working (obviously) but I can`t see where they have been connected, has anyone any info on these points it would be much appreciated.
Cheers
Ganumph

hi
remember "Battling Tops"-"its all in the wrist action!" if you do its probably not the answer!
On my LT there is a 1cm round knob underneath the linkage box only visable from looking underneath;it adjusts the tension. If you have one of these then have a twist. Sorry if it sounds too simple but it caught me out when I had the same problem.
cheers
John

John
Yes I have seen that and had a play about with it but it doesn`t seem to do much, it is gnarled up as if the previous owner has had some pliers on it wonder if the friction part of that is bunged up somehow.
As for battling tops yes I can recall them but only having a poor upbringing never actually had one. snakes and ladders was ok though.

My K75 failed its MoT today with this very problem. I released the throtle cable from the fuel rail end so as to allow more slack at the throttle end. With the cover off twist grip end I released the other end of the cable and have been pouring oil a few drops at a time down the cable- though it seems free enough anyway. Whilst the oil is finding its way to the bottom of the cable I'll give the linkage chain and grip a clean and re-grease but will have to keep an eye on the board here incase someone somes up with the right answer.

There is a little device that clamps onto the cable casing and allows you to force a great deal of oil into the casing to loosen things up. I bought that little gadget at my local m/c store for under $10. Works great.

Just an update on my earlier post. On re-greasing the throttle assembly and re-assembling it was worse than ever! I now realise that the correct grade and quantity of grease is quite important. Too much grease applys a damping action which further slows the snap back action of the throttle. I've now cleaned all the new grease out and only lightly greased it together with some oil and it is much freeer now but still doesn't have the same snap back action that the throttle on my K100 has. Too cold here in UK to spend any more time out in the garage tonight so I'll take another look tomorrow.

This is a NO NO to grease or oil the cables on a K-bike.
The cable as a Teflon sheathing and grease or oil will destroy it.

Mi Amigo
That is what seems to be wrong with mine little and sluggish snap back, I have seen on here not to lubricate the cables I am wondering if it is a culmination of things and if previous owners have oiled the cable it has destroyed the teflon coating. Still unsure about the friction device and I will see if this can be removed altogether to eliminate it. Am on nights at the mo so won`t be doin owt till the weekend. Thanks for your replies.

Not much warmer today out in the garage but I've braved the weather as I only have 10 working days to get the problem fixed and re- MoT'd.

I'm not sure now that the throttle cable is as free as I first thought- or maye pouring oil down it has caused some sort of damping action. In any case, as CrazyFrog points out oiling the throttle cable is inadvised and as MotorWorks here in the UK do both the throttle cable and the throttle bevel/chain link assembly via mail order I think I'll just order these two parts up and change them on spec. I'll report back if it cures the problem.

Right- the new throttle cable and bevel/linkage assy arrived today at a cost of £26. Of course fitting these two items made virtually no difference. Why did I know that was going to happen?

Time to have a closer look at everything. The spring assy on the butteyfly rail had loads of tension so I didn't suspect anything amis down there. Also the original throttle cable seemd free enough but I changed it on spec. Similarly the bevel/linkage assy looks ok to the naked eye but again I changed this on spec and the fact that Motorworks do sell a lot of them. I noticed that with the bevel assy removed rotating the actual throttle hand grip didn't seem too even throughout its rotation. There were spots where you could feel some reluctance to rotate- it felt a bit lumpy in places.

With some difficulty I removed the rubber hand grip cover. This revealed that the hand grip warmer cable had severed- I knew this anyway from previous winter usage. For the time being I simply cropped the wires and fitted rubber sleeving over them to prevent shorting down to earth.

With the throttle grip removed I could see that there were areas of both hardened grease and other areas of corrosion on the handlebar part that the throttle grip fits over. Cleaning off all the old grease, getting rid of the corrosion with careful use of wire wool, and re-greasing seems to have removed the lumpy feel and restored the correct return of the throttle to the closed position. It still doesn't snap back the same way my K100 does but I think it now returns sufficiently to get through the MoT.

I'm wondering if in fact the heated hand grip has become distorted in some way- maybe due to the heating action of the hand grips, and maybe this is still causing some incorrect operation?

Mi Amigo,

The best way to get an answer to your question is to connect the throttle cable on the outside of the bike (going over the tank in a very straight and easy path).
If the throttle snaps back, it will prove that you have some kind of kink in your original installation. When rebuilding my K100, it took me a long time and many tries to find a path offering the least amount of resistance.
The best fit that I found is still not perfect. I believe that the vibrations help bringing the throttle back. It doesn't snap!

Bert

Mi Amigo,
I'm in the same boat, I have to manually twist back the throttle grip to turn down the revs. I have purchased the BMW updated ;
Handle (slip handle W/grip) 32-72-2-311-538
Cam 32-72-1-457-036
and most importantly the Cam Cover 32-72-1-457-037
These 3 items with a new throttle cable is suppose to give you "new" feeling to the throttle. And hopefully the -springback- I miss from Jap bikes
I have owned. I will be doing the change over this winter as time allows. Would be interested to hear from you about this.
Thanks,
Chris

My Beemer passed the re-test today so obviously the examiner was happy with the slow return of my throttle. At least it is returning now which it wasn't for the first test. Many thanks to Crazy Frog and others for their help.

Chris,
I have to say that whilst the throttle doesn't snap back like the Jap bikes (not sure if that is better or not?) at least with Beemers you get a bike that, for instance, still has all the paint clinging to the frame where it was sprayed on in the Bavarian factory 25 years ago. Can't remember many of my Oriental machines looking even half as good after only a few years.
I'll check out your suggestion of the updated handle grip though.

MiAmigo

Perhaps there's a built in slow-to-return-to-idle on our bikes to compensate for light switch-like throttle movements at lower rpm. Fuel injection for motorbikes traditionally has been hard to sort that issue out on if clean emissions is one of the preferred requirements over smooth power delivery and decent fuel mileage. The Oilheads suffered terribly in the early dayz from apparent surging brought on by a too-lean mixture and two relatively large pistons pumping sideways. I think these two issues (surging and the slow return to idle) are fairly closely related since a bike does not have the mass of a car and therefore the twitchy-ness in throttle actuation is felt more acutely on a bike. Dunno for certain, just looking for answers where they can be identified. My K100's (and my K75C) throttles never simply dropped back to idle without some effort.