I just replaced my throttle pipe because my new used 92 CBR had a cracked one due to some unfortunate use from the prior owner. So it's on there, which was fun, but now it doesn't roll off on it's own and pretty much works like cruise control. This is really neat however it has it's flaws which should be obvious... I'm guessing this is because it's brand new and has about 30 minutes of ride time on it, but I don't know since I'm new to the scene. When I first noticed it, for the hell of it I greased the bar and inside of the pipe a bit since I greased the throttle cables where the connect to the pipe, but really this made no differerence. After installation, I checked and I have about 3 mm of play before the throttle would engage, and from what I'm reading this is good. Hope that helps to get an explanation of my new sorta really cool feature.

 

You return spring may be missing.

 

Being new should have nothing to do with it. Either your spring is missing or unhooked like already said, or you have a kink somewhere. If you didnt route the cables the same way, it may be possible that the cables are kinked. It really wont take much to kink them. Something as simple as bending the cables too much or have them twisted will cause this.

as you said, its not a good thing.

The other thing to consider. If you only replaced the tube and not the entire cable, you could easily have a frayed cable. I would suggest replacing the entire cable system, not just the tube if thats what was done.

Also, keep in mind the cables have liners. They wear out and become crimped as well which will abstruct the free movement of the cable.

try turning your handlebars fully one way and fully the other... if it returns easier one way vs the other, your probably routed wrong.

 

When I pulled the pipe, I just disconnected the cable locks or whatever you wanna call those ends from the pipe, slipped it off, then installed the new one. I did not disconnect or do anything with the cables at all. Also the throttle return was working just fine before I installed the pipe so it's definitely something that occurred after and I'm doubting the cables are completely shot with just what I did.

Now for this spring, where is this thing at? Nothing came out of the control from the handle bars, but I can't see it being there either. The Repair Manual is incredibly vague with some real useless pictures when it comes to the components of the handle bar and the throttle cable too. In fact the pipe is actually shown while it's inside the grip.... :| There is a spring that I can sorta see at the point where it connects to the throttle body and when I roll the throttle it looks like that thing is compressing/decompressing. So am I lookin at the right thing?

 

So I've taken this thing and put it back together several times. I sprayed the return spring, and that helped smooth it out a bit. When I pull on just the cables, it's got some good strength on the pull and return so the spring is fine. When I put the pipe on the bar it does have noticeable resistance. When I put the cables on and just the bottom piece it returns but does somewhat hesitate. You can hear the plastic of the pipe rubbing against the plastic of the lower box. When I put the top on and screw it down, you can feel the throttle tighten up more and I haven't even put the screws in completely tight. You can hear the plastic rubbing a bit more with the top on too. I greased it up but not sure if I used a good grease for it... Wheels spin on them pretty good but thinkin I might wanna choose a more viscous grease... Any suggestions? I'm still pretty sure the new pipe is most of the problem, just a hair too large but if there's a special grease I should be using suggestions are welcome.

Got the pipe from bikebandit and it's an OEM... Any problems with them?

 

Return spring should be on your carb/throttle body, check to see of it is seated properly.

Bikebandit is pretty good with OEM parts.

 

You dont have the grip pushed tight against the throttle clamp do you? Loosen the clamp up and pull it away from the grip as you tighten it. it may help.

 

I found the spring last night and sprayed that. It helped some also the routing was wrong so I corrected that last night too. The grip is fine, in fact there's about 1CM between the clamp and grip so no friction there. If I back the pipe off about 1 CM, it spins very free on the bar. If I move it to where it needs to be, it turns but you can feel it grab. I sanded down the bar and the inside of the tube a bit, and it's improved so I'm going to sand it down a bit more later. My theory at this point: The bike was dropped at one point which is why the pipe was busted. I'd say that bar just so happens to have a tiny, unseen to the eye, bend right where the pipe enters the clamp. The old one probably worked fine cuz it was for one, old and eroded enough to casually move around, and two, it was split quite a bit so it was able to compensate for a minor friction point.
Thanks for the replies though, you two helped me knock out a couple other weird things like moving my handle bars to the right would rev up. Knew it was cables but had no idea why.