Topic: #1 carb slide appears to be sticking?

[Chaser60]

Finishing up a build and have run into a problem with the throttle.   At near WOT, I feel a catch.   Then it does not return to closed without assistance.   I can hear a noise and then once i trwist closed past the catch point it returns to close without further assistance.   I have a short video from my iphone (.mov format) that shows the carbs for 1 and 2 cyl.   If you look closely you can see that the #2 actually move up(open) slightly more than number one.   There is also a little loose play in the number 2.  Meaning if I push on the brass colored nut on number one there is almost no wiggle or play.  If I do same on #2, I can move it up and down slightly.

Any ideas on cause or suggestions how to trouble shoot this?

Ok, so I dont seem to be able to post the video.  So first question is how do I attach or post a .mov file?

[ekpent]

If the 4 slides are not moving together a carb synch is in order for starters.

[mickwinf]

two possible things to check, is the flat connector piece between the carbs present, it keeps the proper distance between the two parts. Also check the throttle cables where they attach to the carbs, if wrongly adjusted the thread of the adjuster on the cable can interfere with the cam. 

[Chaser60]

here is video.   The clicking appears to be coming from right between the two mechanisms.   

Understand the idea on bench sync.  What seems strange to me is that this bike did not have this issue before I tore it all down.   I did not rebuild the carbs.   I did have to separate 1 from 2 and 3 from 4 to install new gas lines, but I made sure I did not allow any of the screws to turn.   

http://youtu.be/eaBkxvjfh_0

[Chaser60]

just disconnected the cables for further trouble shooting and also verified that the flat connector is in place and properly installed.   Both items check out ok.

without the cables, it is hard to open the throttle, but I am able to do it and it definately still "catches" / sticks at about 3/4 WOT position.   Any ideas?

[Chaser60]

Pulled the carbs back off the bike.   here is some back ground:
1975 CB 550.   Keihin carbs.   Bike ran very well when I put it in the shop for the restoration in November.   I drained the gas out of the Carbs and they have been sitting since November.

The only thing I did to these carbs is separate 1 and 4 so I could more easily install new fuel lines.   I made sure that I did not turn slider adjustment screws while removing the lock bolt and dust shields.   

As mentioned above, the throttle is sticking.   Now that they are off the bike and I can see the inside I see that 2 through 4 all start to slide open at same time.  However, the slider for carb one is hard to open and lags behind the others.  at about 1/2 throttle carb one seems to stick.    see pictures.

Couple questions.  Is there anything in the above dissassembly re-assmebly that I might have messed up to cause this issue?   

If not, any ideas what may be issue?   here are a couple pics


Note in this second picture how much higher #2 is than #1.   I have the little dust shield off when I do this, but if it was on, the same thing happens, but not as pronounced because the dust shield tries to hold the two aligned.   



Here is video that shows same issue.  I am still not sure how to post video so if anyone can help with that so you dont have to go out to the youtube link, i would appreciate that too.

https://www.youtube.com/watch?v=twMor45J8Ic&feature=youtu.be

Any ideas on causes or how to trouble shoot this?

[Chaser60]

Just separated carb 1.  the other 3 slide very easily.  Slide one is definitely not sliding easily.  I guess it is gummed up...I was hoping..wait, no PRAYING not to have to rebuild these things.   Unless anyone has an idea, I will order rebuild kits and   get started.   

I have been reading the carb FAQ and several other builds.   I know the topic of what kits to buy has been discussed in the past.  Anyone have better luck with any particular maker of kits recently?

 

[harisuluv]

Well what changed before this behavior?  If all you did was take one and four off then put them back on, logically then there's just something wrong with install.  It would seem that something is binding. 

With that being said, that type of sticking looks very much so like lacquer in the emulsion tube which slows travel of the slide down.  Doesn't explain why it would before taking off one and four and then just putting them back on though.

[Chaser60]

Thanks for suggestions.  I took #1 carb apart last evening.   Not bad inside, but the walls of the tube and the slider itself did have dried and gummy gas varnish.   Cleaned with a little  simple green soak and some spray carb cleaner.  Slide now moves without issue.   Have decided to take all four apart and clean them up, new o rings and reuse the original metal parts.   Project for this weekend. 

Wont celebrate until I have this running, but think you guys have pointed me to the issues.     

[harisuluv]

Yeah, that's exactly what it sounded like.  No harm in going through the rest of them while you are in there, if one was dirty, others could be too.