Throttle cable on an old motorbike.

Priapus

Priapus

Priapus

Soldato
Joined
30 Jul 2004
Posts
10,573
Location
East Sussex, UK
Howzit guys,

I have an old motorbike, Yam SR185.

Last night my throttle cable went, so it needs to be removed and replaxced. I phoned the bike shop this morning, they said I can take them the old one and they will get the right cable for me.

Thing is, how the heck do I remove the cable?

I know how to remove it from the handle bars, no problem. However it's removing it from the carb, that sits under the tank, that I just don't know how to remove....

Any ideas guys..?
Im trying to find info on Google, with no luck! :(
 
Yes, the top of the carb has a lid sort of thing, where the cable goes in the midle of it into the carb..

Take it I need to undo that and loosen the cable in there?
 
Yeah thats right it will screw/twist off then the slider will come out attatched to the throttle cable, be very careful with this part.
 
It slots in to the slider just like it does the lever handlebar end. Just be careful not to bend the needle on the slider.
 
Not 100% sure, but on a 2 st carb you unscrew the cap, lift out the slider, (be very careful you don't bend the needle).
The cable goes through the spring and the center of the slider.
To get it off you need to compress the spring with your fingers, and push the cable down through the slider then to the side.
It's quite easy when you can see it all.
This is on a 2 st, but some older 4 st are quite similar.
 
Can anyone show me an example of what the slider looks like, or simler to?

Sorry, never done this before, and really need to get the bike running again.

At the moment, when I open the throttle, it stays open. And will close only if I close the throttle lever and it will close the carb or cable a few seconds later, like the cable is bent inside or something.

Will take it all apart tonight.

Thanks guys!
 
15carbslide5px.jpg


You can preety much work it out from that but once you get cracking it will all come clear.
 
Trixter said:
15carbslide5px.jpg


You can preety much work it out from that but once you get cracking it will all come clear.
Click to expand...


Ok. But what confusses me is, what does the cable pull that allow you to go faster. Obviously its a mxture of air/fule. Does it open a flap or what?
 
The needle is tapered so when you pull the cable, the slider lifts up (allowing more air though), the needle also lifts to let more fuel through the main jet.
 
Yeah the cable pulls the slider and needle up (hence the spring to push it back in place) this opens up the entrance of the carb leading to the engine to let fuel/air in, in normal postition the slider is blocking this off.

It will be better once you see it.
 
Okay, no problem.

Thank you guys. Great help! :D

It's strange that it started now, and is so bad. I would've thought if the cable was damaged it would've gotten worse as time went on. Could it be the problem in the grip, where it winds up, got caught or something?
 
If the sticking has just started, check other things before you change the cable.

Is the throttle grip touching the handle bar? Loosen the assembly and slide it out slightly.

Is the end of the grip missing? Dirt can get between the throttle slide and the handlebar causing it to stick.

Take the top off the carb, then twist the throttle. is it still sticking?

Make sure the cable has been routed properly. An ill fitting tank can jam a cable.

Cables can split which then corrode causing it to stick, then you need a new cable.
Good luck.
 
It could be a number of things, best way is to inspect everything.

A mate had the same problem a few weeks ago on a RS125 it was the actual throttle body causing it, this happened all of a sudden too but a peice of plastic had snapped inside it, thats what caused it.
 
Well, I was rining on the highway when it happened. I didnt notice too much what was actually wrong, because I had the throttle in one opstion all the time.

Okay, so I open the throttle and let go. It will remind in the state until I close it. Now if I manualy close it, the engine will still rev high like its open, will do this for a few seconds and will very slowly drop back down till it is actually closed.
 
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