new throttle won't return on it's own

[KentMoney]

hello wonderful xs650.com community,

I recently bought a new 7/8 throttle from a local British bike supplier. It is the classic style with metal housing and a metal throttle sleeve. I hooked it up but now I find that the throttle won't return after twisting it. it is as if the carburetor springs aren't strong enough to return the throttle to idle position. But they were working for my old plastic throttle sleeve set up...

am I supposed to grease up the area where the metal throttle sleeve sits in the housing? Should I grease up between the handlebars and the inside of the throttle sleeve? Any solutions?

Thanks!
Kent

 

[xjwmx]

Yes, but a very light coat of grease so it won't cause sticking later on. You might need to smooth off some flash with a pocket knife too. Also, don't let anything that's supposed to turn push against the end of the handlebar and drag on it. Then get some 10w-30 and a soda straw or hollow coffee stirrer and use it to pick up some oil, put your finger over the top, and let it run down the cable. Do it until oil runs out down at the carb. The throttle needs to slap back with a clunk, when you let it go.

 

[mouser]

routing the cable correctly is imperative....had the same prob...

 

[KentMoney]

when I set it up with the most direct cable routing possible, it was still binding and not returning. I will try lubing the cables up and the mating surfaces between the throttle housing and sleeve. Will report back.

 

[69er]

same problem..added a extra return spring.. (butterfly's fit perfect and carbs are synced..)

 

[mouser]

If it is any help I had to rout a problem replacement cable, after a drag bar installation, between the fork tubes from the front. Under not over the front tank mount. Cross over the frame tube about half way and come out, in front of the fuel petcock...then it suddenly worked fine. I found it must be secured to the frame at the point it crosses over the backbone with a zap strap. Then it was all good...these bikes are fussy about clutch and throttle cable routing...IMHO

 

[Maddog Marty]

Make sure your new throttle assembly is not pushed too far onto the bar, making the bar drag against the inside end of the grip.

 

[mouser]

I am considering eliminating the throttle cable entirely and installing an on/off switch in it's place....

 

[Stone Hands]

Stone Hands here. I have the same problem with my rebuilt 72 XS2. When I pulled the carbs to dunk and clean the throttle had a healthy return chunk when released. Carbs back on and they will not return. The carbs are not the problem as when moved by hand they have great return tension. I do not have the tank on as I pulled it to de-rust. On a standard XS2 the cables route under the tank but with the tank not even on I am not sure why the throttle does not spring back. What does the spring on each cable function to do where does it get positioned. Is there a diagram for the normal routing of the cables?

 

[Maddog Marty]

yes, for sure there is a routing diagram. I have one for my '75B in the Service Manual, yours may be different. As stated above, evidently cable routing is (sometimes mysteriously) critical on these bikes.

 

[Stone Hands]

Thank you. Makes sense. I will try to find one. Does not appear that there are many ways to route the cables but as both are binding it could be routing or my throttle itself. It does not feel smooth when you twist. I feel some grabbing when the cables are not even attached to the carbs. Will let you know and thanks again.

 

[Maddog Marty]

Cool...as I stated above, make sure your throttle assembly is not pushed too far onto the handlebar because I've seen that happen on dirtbikes and the throttle will drag because the inside of the grip-end is dragging against the bar-end, inside. Check each component for free movement and you will find the problem.

 

[XSLeo]

Are there any burrs or rough spots on the bars where the throttle sleeve fits on the bars?
With out the cables attached and just the throttle tube, put it on the bars, does it spin on the bars freely?
Without the cables does the thrittle tube spin freely in the housing?
Check all these things. I put a set of ATV bars on my 75. There were burrs around holes drilled in the bars that kept the throttle from working without binding. You might even have to sand off the whole area of the bar under the throttle.
Leo

 

[KentMoney]

Problem solved. I ended up sanding the handlebars and putting some thin oil between the sleeve and bars. Solved the problem.

 

[Stone Hands]

Great idea. Funny thing was when I took the carbs off there was not a problem. Putting them all back together and now they find. I feel something rough regardless. Last night I found a couple of small burs on the cable ends that may have occured when I dismantled the carbs. They have been on and off a few times. I have new cables from Mikes XS and will replace and add your suggestions when I reassemble. Thanks for the ideas.