butterfly servicing

[wan3417]

After cleaning the butterflys with brake cleaning fluid ( spray ), they remain free for about 2 days only, just to stick back once more. How else can the butterflys be serviced? Can they be dismantled and cleaned? What must I be aware of?
My bike is a 1982 GS1100EZ which was left idle for nearly a year. My ignorance was to leave balanced fuel in the tank and carbs thereby creating this issue of a 'gummed up' carbueration system. Over a period of a year, had them serviced 2 x but each time after 2 or so weeks, ended up stuck once more. Bought some fuel additive and am planning to flush out the fuel tank of residual fuel too. Can this additive be used as solvent for the butterflys too? Seems like they are gummed up inside the shaft they are fixed to. How to penetrate the shaft they rotate about?
Thanks for any advice that can solve this issue. Itching to ride the bike again but frustrated with this re occuring problem.

patrick

[JamesWhut?]

You don't want to go there unless you absolutely have to. The screws that hold the butterfly valve disks are very small and highly torqued. They are easy to strip and ruin. Dipping the carbs in cleaner usually works to free up gum buildup in the pivot shaft. No fuel stabilizing additive won't really help this. Mainly what you need to do is just get some carb cleaner (not brake) in there maybe some penetrating oil, and then work the gunk loose, and then keep spraying them and turning until they get clear enough to stop gluing up.

[wan3417]

I also noted on the carb rebuild papers that the carbs can be dis assembled individually. Would it be better to soak the butterflys and it's shaft in carb cleaner fluid as seperated units? Are there any o-rings etc that can be damaged while soaking in carb cleaner? All this is new territory for me, sorry if I sound a nerd. Thks for the info, much appreciated.

patrick

[londonboards]

Depending on your level of technical expertise and confidence, you can certainly dissemble the throttle butterflies. I was a beginner when I did it. Just get some new screws for the butterflies as they will be damaged getting them out AND support the throttle rod from behind as you apply pressure in undoing those screws. Make sure you thread lock them back in and peen them over so they can't come undone.

There are rubber O rings between the throttle rods and the bodies. They can perish. I found one missing on my project:



There are some more tips here:

Butterfly Capers

[phydeauxmutt]

As you have discovered, BRAKE cleaner is for brakes, not CARBS. The brake cleaner has likely attacked the rubber seals on the throttle shaft, so no matter what you use in there now, they will probably stick after a while. Replacing the seals would be the best way, but as others have noted, you have to be VERY careful.

The screws are not really torqued in that tightly, but the ends are peened (flared) to ensure that they don't come out while the engine is running. As you try to remove the screw, you will be forcing the flared metal back into its original shape, making removal rather difficult. When you re-assemble, peening the screws is ideal, but you might find some chemical threadlocker. No idea what you have available in your area, so good luck.

[hillsy]

The brake cleaner has likely attacked the rubber seals on the throttle shaft

Brake Cleaner does not attack rubber - if that were the case then you wouldn't be able to use it on brakes...

What it DOES do is remove any oil / lubricant on the shafts and therefore can make them bind. You need to lubricate the shafts.

[JamesWhut?]

It can attack plastics and rubber seals. Spray some on an ABS or painted surface. It doesn't effect the "rubber" of the brake lines because it is formulated to resist brake fluid. The plastic bits in carbs are not.

[dantodd]

I think the take away is.
Next time use can cleaner.
Removing and repairing the butterflies is really tedious but possible
Try lubing first, if you haven't already, to avoid having to disassemble them.

[Nessism]

You might want to try a few drops of light oil on the shaft. You probably have some varnish build up in the gap between the shaft and carb body. Typically that will work it's way out once you put the bike back in service.

[JTGS850GL]

As stated above, the throttle plates are NOT heavily torqued down. They are just peened over on the backside of the screw. You shouldn't need to remove them to do a proper cleaning. If you have not done so, then it may be time to disassemble the carb bank and do a good strip and dip along with replacement of all the o-rings.

Here's the link to the carb rebuild tutorial:CV carb rebuild tutorial


It pretty common for the throttle shafts to be a little stiff after some intense cleaning. Use some Wd40 or light machine oil and spray it on both sides of the shaft on each carburetor. Move the throttle plates back and fourth and that should free everything up nicely.

[hillsy]

It can attack plastics and rubber seals. Spray some on an ABS or painted surface. It doesn't effect the "rubber" of the brake lines because it is formulated to resist brake fluid. The plastic bits in carbs are not.

We're talking about seals - which brake cleaner does not "attack". There are rubber seals and dust covers in calipers and brake cleaner does not "attack" them.

Mind you, brake cleaner is designed to be sprayed on and then it evaporates away. If you soak stuff in it for a period of time it's probably going to be a different scenario.

I've used brake cleaner for years to clean out carbs but I immediately dry them with compressed air so they do not soak in the stuff. Never had a problem using it that way.

[chuck hahn]

IF you brave up and remove the butterflies, you can use a pair of needle nose vice grips to squish the bolts again..and as mentioned before some gas resistant thread locker will help too.

[wan3417]

Everything has been stripped off and the carbs seperated. I plan on soaking the butterfly shaft area of each carb seperately in heavy duty gas injector fluid and work out the gum that causes the stickiness there. Can this damage the butterfly component? Are there any other o-rings inside the carb body housing that pivots the butterfly I should be aware of?
PS
How do I attach pics here?

[londonboards]

Look at the picture in the post above. There are rubber seals in those shafts. You need to get the shafts out and replace them.

[wan3417]

Yes, Richard I have removed the rubber seals from the shafts and will be replacing them. Afterall they are already 34 yrs old ☺. Looks like the butterflys are free of gum now after cleaning and working them out. Now to clean out the petrol tank of petrol residue ( more than a year of old petrol that has evaporated and clung to the inner sides. I'll be puttjng in some new petrol with carb cleaner for this. A lot of soaking and swishing around to dislodge the residual. Anything I have to be aware of regards the petrol cock and maybe the petrol gauge sensors? Any rubber seals there?