Carb QWESTION

[kirmit77]

What is the best way to clean the outsides of the carbs? Mine are pretty dirty. Is there something I can soak them in or maybe take it to get a acid bath? HELP!

[Ivan]

The high pressure wand at the carwash. If you get fancy, you can find one that has engine cleaner and prewash it with that. While you're at it, get the rest of the engine too.

No joke, thats how I clean mine up. Usually every other week or so. Works well.

I guess I should mention that is while they are installed on the bike. I just ride there blast it and ride away. Usually give it the 100 mph air dry after.

[kirmit77]

Well the thing is im taking everything off to redo. Internals are pretty bad for just having 9800 miles on it. Just has not been rode since '85!

[dbeardslee]

A friend told me the other day that Scrubbing Bubbles was an excellent engine cleaner. He was talking about cages, but I'm gonna try it on Betsy when the weather gets warmer. I cleaned the outside of my carbs with a green scotch-brite pad and elbow grease, and it worked pretty good. This was after getting all the gunk off with brake parts cleaner.

[Ivan]

Well, depending on your competence level, I would use the caustic carb cleaner. You will be warned several times about NOT using this, since the throttle shaft seals will be destroyed in the process. I avoided this situation when I rebuilt mine by taking the butterflies out and removing the shafts. To do this, you will need a dremel with a grinding stone to grind the back of the little screws that hold the butterfly to the shaft. Those screws are staked on the back. Once it is time to put them back in, they need to have a center punch used on them to stake them again. Having a little screw go through the engine makes big problems.

If you are not 110% sure you can handle this, don't try. Stick with the brake parts cleaner and a scrub brush.

[tarzan]

I dissassemble one carb at a time.This ensures that the parts dont get mixed between carbs .Also if you forget how something goes you have three to look at.I also soak them in carb cleaner(1 gallon can).I disassemble but leave the butterflies in.Then hang the carb in the cleaner with coat hanger wire.I keep the butterfly shaft seal above the fluid.You can get the bottom submerged this way and clean the passages well.Then I remove after about half an hour and use a toothbrush to scrub any dirt and grunge left on them.Then I spray them off a bit with spray carb cleaner.Then I wash them completely with soapy water,then rinse good with clean water.Then I use compressed air to blow off the water and to make sure the passages are clear.It sounds like a lot of overkill but you only want to do this once right?

[fredintoon]

What is the best way to clean the outsides of the carbs? Mine are pretty dirty. Is there something I can soak them in or maybe take it to get a acid bath? HELP!

Hi Kirmit,
toothbrush and acetone.

[kirmit77]

Diaphrams

Do i clean the upper parts the same? or is there something different? I have a manual coming and should be here on friday

[dbeardslee]

When you remove the top, carefully loosen the diaphram from its seat. Take a finger and stick it in the throat of the carb and push up on the cylindrical part of the emulsion needle assembly and it should come free at the top. You can then withdraw the assembly from the carb. Wet a rag with a little carb cleaner and just wipe the varnish off the cylindrical part being careful not to get it on the diaphram. Might want to inspect the diaphrams for holes by holding a bright light up to them to see if any light shines through. Wipe the needles off and put the assemblies in a safe place - they're VERY expensive.

Assuming you have dissassembled the lower part of the carbs, you can then withdraw the emulsion tubes. Might need to spray some carb cleaner or penetrating oil on them to loosen 'em up. Can't remember which side they come out from, but it should be fairly obvious. The end of the emulsion tube will be directly under the main jet and washer. If I remember correctly, that's where you need to apply pressure, but I wouldn't swear to it. You'll have to use something to push them out that won't damage the brass. A wooden dowel of the appropriate diameter should do the trick. You can then clean the upper part of the inside with a little carb cleaner (or your solvent of choice) and a toothbrush as per Fred's recommendation. I have a paint sprayer cleaning kit that has a number of cylindrical nylon brushes that work well for cleaning the area the emulsion tube lives in. A good soak in carb cleaner and scrub should take care of the emulsion tubes themselves.

Make sure you keep all the parts for each carb separated if you dissassemble them all, or do them one at a time to avoid confusion.

[DGXSER]

Yep DBeardslee got it. Push from the main jet side on the emulsion tube. Wooden dowel works great.

[SFerinTEXAS]

tubes

I personally am interested in knowing about the emulsion tubes . Watch carefully the for how many side holes are in 2 and 3 compared to 1 and 4 . If no one has been in these carbs before they should be original per the factory. please let me know .

[DGXSER]

Hey SFer, there are many here with more experience than I have in these carbs. As far as I have read or seen, the only thing that should be different in any of the bank is the main jet in the center two carbs were one size larger on some years, and only on some of even the same model in the same years. For intance, on my SH, the mains are 110s. The center two were 120s on some of the ones made. Mine had 110s straight across, and many have reported the same. The theory I have heard is that it was doen to keep the center two cylinders cooler since they have less air exposure.

I have never heard of the emulsion tubes being different other than a PO error, or a mishap in ordering parts.

[red bandit]

On the 79 special the emulsion tubes in 1 & 4 have 16 holes around the diameter and the tubes in 2 & 3 have 12 holes. The holes are air holes so less holes in 2 & 3 is richer.

[SFerinTEXAS]

All in all I'll stick to my original request of kirmit77 Thanks guys. The ones I placed in my centers had 10 holes IIRC by the way. But like many others I wasnt paying attention when I first disassembled them. Tell me what you find kirmit.

[kirmit77]

kinda confussed?!?!

what are these emulsion tubes and what do they look like(where are they located)