Author Topic: sticking..everything?  (Read 1977 times)

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sticking..everything?
« on: March 19, 2011, 11:05:18 PM »
so ive been searching, reading, searching, reading.. and yanno.. searching and reading. but cant seem to find an answer to my question(s)

81 CB650C. carbs were rebuilt ~a year ago, but then bike sat for a year before i bought it. i have a peculiar issue.

a. im fairly positive they werent synced. something doesnt sound quite...right... and the bike doesnt really like to hold an idle. which leads me to

b. bike fires right up with the choke plates completley closed.. the issue i have is the choke sticks. bad. by hand i can adjust it, and i can feel tension on the arm when i do so.. but no matter what i do i cant get it to spin freely as its designed. how do i go about fixing this? any tricks?

c. the throttle sticks. bad. ordered a new throttle as it seemed that the grip was sticking in the housing and for 7$ i really didnt think twice about it. I went to pull it off the handlebars and swap them out.. and off the handlebars, the throttle spins as it should. pulls back and everything. yet the SECOND i slide it back onto the bars (no matter whether its greased, ungreased or the type of grease.. it sticks bad. is this suspect of a weak throttle return spring? or of the throttle itself? the cables dont seem to be binding as i can move them by hand fairly easily.

d. the tach works.. kind of. it just sits at 2,000 rpm. rev the bike. sits. bike idles, it gradually climbs to 2k and just sits there. any ideas? the only info i can find is on the SOHC tach and how the o ring on the end of the cable tends to leak causing the tach to malfunction. im befuddled.

any and all help is greatly appreciated.

also.. heres a video of the bike starting etc. please let me know if it sounds like something is terribly wrong as im new to this whole thing..

[youtube=425,350]-Oueeu60wIM[/youtube]

and a picture, just because :)

Offline Gordon

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Re: sticking..everything?
« Reply #1 on: March 19, 2011, 11:26:36 PM »
a.  There's no air box attached to your carbs.  If the carbs haven't been re-jetted and adjusted to compensate for this, then the engine won't idle or run correctly. 

b.  The '81 650C should have the choke controlled by a cable with a knob up at the handlebar.  The housing just below the knob end turns to adjust how tightly it clamps the cable. 

c.  Sounds like the throttle cable may be routed incorrectly so that it's binding when everything is hooked up.  There should be no sharp bends.   

Offline Retro Rocket

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Re: sticking..everything?
« Reply #2 on: March 19, 2011, 11:30:55 PM »
I read somewhere that the 650's don't like pods at all so i guess it is even worse with nothing at all. Chase up an original airbox, that should be a least a good starting point..
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Offline Gordon

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Re: sticking..everything?
« Reply #3 on: March 19, 2011, 11:48:49 PM »
For the throttle grip, you may just have a lot of gunk built up on the inside of the throttle sleeve.  The PO may have tried to lube a dirty throttle assembly, which only attracted more dirt causing it to build up more and stick. 

For the sticking choke assembly, it may be time to pull the carbs to get a better look at what's going on and to be able to better clean everything up. 

Offline Pinhead

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Re: sticking..everything?
« Reply #4 on: March 20, 2011, 08:28:55 AM »
For the throttle grip, you may just have a lot of gunk built up on the inside of the throttle sleeve.  The PO may have tried to lube a dirty throttle assembly, which only attracted more dirt causing it to build up more and stick. 

For the sticking choke assembly, it may be time to pull the carbs to get a better look at what's going on and to be able to better clean everything up. 

kind of figured i would have to pull the carbs. not excited about it, but it could be alot worse haha. what would you recommend to use while cleaning the throttle assembly? all of it? i think i may wait until my new bars come in as ill have to pull everything off then anyways.

another quick, more ridiculous question. the baffles in the exhaust pipes are rusty and ugly as all hell. if i drilled the rivets, could i remove the baffles and contents of the mufflers? essentially creating a straight pipe while cleaning the whole thing up?

My 650 wouldn't even start without the airbox so you're doing a little better. ;)

Yes, you can remove the rear baffles. It'll sound good. Just remove the rivets and pull the rear baffles out (they look like 6-inch long glasspacks). It can be a major undertaking, though; they'll be carbon-packed and very tight. It'll seem like they're still attached somehow on the inside, but they're not.

If you want to make it easier, remove the entire assembly (headers and all) and soak the mufflers in something that will clean away carbon. You just need to soak the last eight inches or so, so about 10" of cleaner in a 5-gallon bucket would work.
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Offline Pinhead

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Re: sticking..everything?
« Reply #5 on: March 20, 2011, 08:53:45 AM »
this concept is blowing my mind haha coming from the automotive world, i never would have imagined that a missing airbox could cause so many problems.. like not starting haha. damn now i cant wait for it to get here!! do you think a body panel puller or slide hammer would help with the baffles? is there a chance of them shredding or can i just wail on them till they pop loose?

I used vise grips and a hammer. Slide hammer would definitely work. You probably won't get them out without tearing them up unless you soak them to remove the carbon.
Doug

Click --> Cheap Regulator/Rectifier for any of Honda's 3-phase charging systems (all SOHC4's).

GM HEI Ignition Conversion

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By the way, I'm going for the tinfoil pants...so they can't read my private thoughts.
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Offline Pinhead

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Re: sticking..everything?
« Reply #6 on: March 20, 2011, 09:30:11 AM »
I didn't have to, though I didn't have to re-jet even with straight pipes...
Doug

Click --> Cheap Regulator/Rectifier for any of Honda's 3-phase charging systems (all SOHC4's).

GM HEI Ignition Conversion

Quote from: TwoTired
By the way, I'm going for the tinfoil pants...so they can't read my private thoughts.
:D

Offline Gordon

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Re: sticking..everything?
« Reply #7 on: March 20, 2011, 06:31:17 PM »
For the throttle grip, you may just have a lot of gunk built up on the inside of the throttle sleeve.  The PO may have tried to lube a dirty throttle assembly, which only attracted more dirt causing it to build up more and stick. 

For the sticking choke assembly, it may be time to pull the carbs to get a better look at what's going on and to be able to better clean everything up. 

kind of figured i would have to pull the carbs. not excited about it, but it could be alot worse haha. what would you recommend to use while cleaning the throttle assembly? all of it? i think i may wait until my new bars come in as ill have to pull everything off then anyways.


Pulling and cleaning out the carbs is a rite of passage for every sohc4 owner.  Aerosol carb cleaner and compressed air will be your best friends.  If you do pull the carbs, go ahead and pull all the jets and emulsion tubes, make sure all the tiny holes in each of them are clear, and spray carb cleaner and then compressed air through all of the fuel/air passages in the carbs.  Then clean out your tank, clean or replace the fuel lines, and make sure you have a clean, intact fuel filter.  You don't want any rust particles or other debris getting into and clogging up your freshly cleaned carbs.

If you do things methodically and thoroughly you won't have to do this again as long as the bike is ridden on a fairly regular basis.

Offline Gordon

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Re: sticking..everything?
« Reply #8 on: March 20, 2011, 06:55:41 PM »
For the throttle grip, you may just have a lot of gunk built up on the inside of the throttle sleeve.  The PO may have tried to lube a dirty throttle assembly, which only attracted more dirt causing it to build up more and stick.  

For the sticking choke assembly, it may be time to pull the carbs to get a better look at what's going on and to be able to better clean everything up.  

kind of figured i would have to pull the carbs. not excited about it, but it could be alot worse haha. what would you recommend to use while cleaning the throttle assembly? all of it? i think i may wait until my new bars come in as ill have to pull everything off then anyways.


Pulling and cleaning out the carbs is a rite of passage for every sohc4 owner.  Aerosol carb cleaner and compressed air will be your best friends.  If you do pull the carbs, go ahead and pull all the jets and emulsion tubes, make sure all the tiny holes in each of them are clear, and spray carb cleaner and then compressed air through all of the fuel/air passages in the carbs.  Then clean out your tank, clean or replace the fuel lines, and make sure you have a clean, intact fuel filter.  You don't want any rust particles or other debris getting into and clogging up your freshly cleaned carbs.

If you do things methodically and thoroughly you won't have to do this again as long as the bike is ridden on a fairly regular basis.

these would be my first bike carbs, but i rebuilt the edelbrock on my porsche many times before i sold it (today actually). i mean they were just cleaned/rebuilt less then a year ago. you think that could be an issue? i checked all the lines, petcock etc. its not a fueling issue. or are you saying that the sticking things could be because of that? but then what would the jets and emulsion tubes have to do with a sticking throttle or choke?

The jets, emulsion tubes and carb passages have nothing to do with the sticking choke and throttle, but while you have the carbs off to figure out and fix that problem you may as well clean everything out really well yourself.  Never trust the work that the PO did, or said they did, when you can't see with your own eyes or can't verify by other means that it was done well.  

Offline scunny

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Re: sticking..everything?
« Reply #9 on: March 20, 2011, 07:07:15 PM »
if the carbs have been de racked, they might not back together square binding the choke linkage.
past-cb100,ts250,cb500,cb500,gs1000,gs650g.phillips traveller
present-CB 650 retro
            VTR1000F3
           XL250S riverbed rocket
           TS250[sold]
           TS185[sold]
           XL125S[sold]
           MT50 (white)
           MT50 (red)[sold]
           KN250/XS400 project
           XR/XL250 bitsa under construction
           SL100[sold]
           XL250R
           pedal(pub bike) leaks oil
my gallery http://gallery.sohc4.net/members/personal/scunny

Offline scunny

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Re: sticking..everything?
« Reply #10 on: March 20, 2011, 07:49:51 PM »
you will need to pull them off the bike to see properly. they have a mounting plate and held on with machine screws. just loosen them up and then retighten, checking operation as you go.
past-cb100,ts250,cb500,cb500,gs1000,gs650g.phillips traveller
present-CB 650 retro
            VTR1000F3
           XL250S riverbed rocket
           TS250[sold]
           TS185[sold]
           XL125S[sold]
           MT50 (white)
           MT50 (red)[sold]
           KN250/XS400 project
           XR/XL250 bitsa under construction
           SL100[sold]
           XL250R
           pedal(pub bike) leaks oil
my gallery http://gallery.sohc4.net/members/personal/scunny