Sticking throttle...

[Steve91T]

Took the carb off to find that it's not the cables, it's the throttle assembly. I've also ruled out the slide.

I sprayed the whole thing down with carb and choke cleaner, didn't help at all.

Has anyone else had this problem? Did I get some junk in the throttle wheel assembly? I'm assuming I'm going to have to take the whole thing apart.

Anyway, just thought I'd ask here before digging into it.

Steve

[Debi]

Check the throttle housing....could be up there.....also mine had that issue and it turned out to be the return cable:thumbsup:

[schrode]

are you running hand guards? if the throttle housing slips to the bar end then sometimes the grip or tube rubs the guards and causes it to not return normally.

[Steve91T]

Thanks guys, like I said its not the cable. On the bench, the last 1/2 travel of the throttle wheel is very hard, and once at WOT, it'll stay there. Its something in the carb itself.

Steve

[schrode]

bent needle?

[Wayward Son]

did you have slide out of the carb?

[Steve91T]

Needle is out and straight. Wasn't binding are all. I didn't get a chance to pull the slide. I did remove a screw that allowed the slide to have some play. It moved freely, while the throttle wheel was still binding. Not really sure what happened, this came out of nowhere.

I'm thinking something in the throttle wheel, and whatever connects it, has dirt or something in it. It was dusty the day it started to bind. Is there a seal that could have failed?

Thanks

Steve

Edited March 27, 2010 by Steve91T

[einfahrt]

The needle floats with the slide. The slide has no connection with the mechanical linkage except by engine vacuum/mass flow of the instake air. Only the butterfly is connected to the cable. If the butterfly shaft rotates shut but the throttle sticks, it's a problem in the slide.

I'm very picky about a smooth and easy throttle, and find the dual-cable setup first introduced by Honda on their 4-S singles long ago to be an unfortunate turn of events in design. Unfortunate, as two cables are an unecessary complication that like kickstand switches, causes more problems than they solve. Most bikes still have ony a single cable, and these bikes are identical to them except for the added cable.

I always remove the pull-shut cable, lube the remaining pull cable and carefully adjust it. I use oil between the throttle pipe and bas (not grease). The result is my throttles are always super easy to pull and always will flick shut immediately when you let go of the grip.

This suggestion sometimes provokes protest from the 'gotta be there for a reason' crowd. If you don't understand fully how these things work and aren't comfortable with my suggestion, simply don't do it.

[Steve91T]

The needle floats with the slide. The slide has no connection with the mechanical linkage except by engine vacuum/mass flow of the instake air. Only the butterfly is connected to the cable. If the butterfly shaft rotates shut but the throttle sticks, it's a problem in the slide.

I'm very picky about a smooth and easy throttle, and find the dual-cable setup first introduced by Honda on their 4-S singles long ago to be an unfortunate turn of events in design. Unfortunate, as two cables are an unecessary complication that like kickstand switches, causes more problems than they solve. Most bikes still have ony a single cable, and these bikes are identical to them except for the added cable.

I always remove the pull-shut cable, lube the remaining pull cable and carefully adjust it. I use oil between the throttle pipe and bas (not grease). The result is my throttles are always super easy to pull and always will flick shut immediately when you let go of the grip.

This suggestion sometimes provokes protest from the 'gotta be there for a reason' crowd. If you don't understand fully how these things work and aren't comfortable with my suggestion, simply don't do it.

I have an E, which is mechanically linked. Also, if I didn't have the pull, my throttle would have stuck. My cables are fine, something got gummed up in the Carb.

Thank you anyway,

Steve

[tiemann1]

Usually when my E model sticks I find the problem is in the R6 throttle tube I use. A couple of weeks ago I finally got around to throwing away the black plastic carb cover on the right side that covers the AP and carb throttle wheel. When I put my Acerbis tank back on, my throttle would sometimes stick. The problem was the clutch cable was rubbing on the carb throttle wheel causing the wheel to stick occasionally. No problem, just moved the clutch cable and zip tied it back in place away from the carb throttle wheel.

[Steve91T]

I appreciate the suggestions, but like I said, the Carb is on the bench. Its sticking and binding while on the bench. Has nothing to do with cables, or anything on the bike.

Steve

[Lob]

did you disasseble it?

look at slide rollers, slide arm rollers

and throttle shaft needle bearings

....if we are talking about FCR

[Steve91T]

I'm out of town right now, but get home Tues. Ill take it apart then. I hope it not the bearing, I plan to do some riding.

[Lob]

yep, better if not the bearings.

i haven't seen these as parts on any fiche, may be some OEM would fit..

[manganos]

Did this start happening when we rode last?

I got home and put my bike in the garage.....came back from work and the entire garage floor was coated in gas!!! My carb is now leaking pretty bad ...grrr bad mojo man!

[Steve91T]

Did this start happening when we rode last?

I got home and put my bike in the garage.....came back from work and the entire garage floor was coated in gas!!! My carb is now leaking pretty bad ...grrr bad mojo man!

No kidding, yeah it happened on our ride. Too much dust and stream crossings?

[einfahrt]

I have an E, which is mechanically linked. Also, if I didn't have the pull, my throttle would have stuck. My cables are fine, something got gummed up in the Carb.

Thank you anyway,

Steve

Sorry, not familiar with the E model. All the small dualsports I have had and now have are with CV carbs that have no direct mechancial linkage, so I assumed....

Now every motorcycle I have had running back 40 years with direct linkage to a slide have had single cables. I should take a video of my now-modified single-cable setup. Open it up and let go and there is a fast 'thwack!' as the butterfly closes with immediate authority. The dual-cable setup when well lubed and adjusted does work well depending on throttle design and cable layout. But I am picky sort when it comes to controls and want things just so. Guys who hop on my bikes almost invetiably make some comment about precise and very smooth controls, so I must be doing somethng right:smirk:.

[Steve91T]

Well, I found the problem. After taking the slide out and finding that the slide was in fact not binding at all, I then removed the spring on the rotating assembly. It wasn't binding either. It was actually the idle adjust shaft that runs along the AP arm. It somehow got bent and was rubbing against the AP linkage arm. That was it. I don't know how I didn't see that before, but oh well.

BTW, getting that spring back on was NOT FUN!

einfahrt, I totally understand what you mean about removing the return cable. But actually, in my case, I would have been in trouble because the throttle could have in fact stuck WOT. Everything was adjusted properly and I didn't have any problems before, somehow it all of a sudden decided to bind.

On that note, while I was in there, I lubed up a new pull/pull throttle cable and removed the old one. It was in pretty bad shape. Lots of resistance. The new cable definitely makes a huge difference in how my throttle operates.

Anyway, thanks for the help guys!

Steve