Bladerunner -
Do your carbs have diaphragms? You can tell if you have a plate on the top of your carbs (which I think all do) held on by screws (or similar). Once you remove the plate (cover), you should be looking down at what will appear to be a rubber cone (or 'sheet,' for lack of a better word). Your carbs should also have cylinder-looking things in the actual carb itself, if you were to peer down the throat. It should move up and down, revealing the main fuel needle when you lift it up. I think these are called 'slider' carbs? I may be wrong, but that's my nickname for them for now until someone sets me straight
.
Anyway, these carbs will have a main 'throat' for air to pass through and collect fuel from the main needle or idle jet, etc. But they should also have another, much smaller channel up top of the throat.
I have found a picture on the net with what my (our) carb looks a lot like, and due to the fact that this is my first post on any forum (glee!!) I don't know if it'll show up right, but here goes:
(
http://www.teamcalamari.com/pix/20mm/14b.jpg)
Looking into the throat of the carb, we see a large brass-colored 'slider' and attached below the main needle. Mine is actually black plastic, and yours may be as well, however this picture will demonstrate my purpose just fine. That slider should move upward, as to allow more air to pass through, and expose more of the needle. Now, for anyone who may not know exactly how carbs operate, the needle is tapered, meaning it comes to a point like a No.2 Pencil (to put not too fine a point on it, if you'll excuse the pun). The purpose of this is to allow a metered amount of fuel to be sucked out of the bowls. How? The needle fits into a hole. Imagine sticking a pencil into a straw, and trying to flow fluid through it. It shouldn't at all. Now imagine if you pulled the pencil out just slightly, and now fluid flows slowly around the pencil tip. Pull the pencil completely out, and the fluid flows as fast as the straw will allow.
And now back to our point: The upper hole allows vacuum to be drawn on the top of the diaphragms. This negative pressure causes the soft rubber (or similar material) diaphragm to be sucked upwards. The 'Sliders' are attached to the underside of the diaphragm. When the diaphragm gets sucked upward by the negative pressure, it pulls the slider up with it, allowing more air into the carb. And attached to the slider, is the needle, so when the slider moves upward, the needle also comes up and allows more fuel to flow between it and the hole it fits into. Make sense so far? (and if I'm just toootally wrong here, which I admit fully that I may well be, I hope someone will set me straight
. I'm pretty sure I'm close, though.)
Because of the major role the diaphragms play in all this, they are, in fact, a critical element of carb functionality. If you tear the material, the negative pressure will just suck air through the tear, and the effect is completely lost - that carb will be forever stuck at 'idle' position (or worse than idle).
Now, the reason for the LENGTHY, lengthy lecture is to point out that not only are the diaphragms important, but they are also very sensitive. It is recommended that such diaphragm carbs are treated VERY carefully when cleaned, as many strong/caustic cleaning agents will just MELT through the diaphragms. So here is what I will tell you that I did:
I bought a can of Chem-Dip as (hopefully) pictured here:
http://ecx.images-amazon.com/images/I/31YRRAQ9Q0L._SL500_AA260_.jpg
This stuff is AMAZING, but is also VERY strong. what I did was, remove the carbs as a whole, remove the bowls, and purchased a small oil drain pan just large enough to span the length of the carbs. I sat the carbs in, without the bowls, and filled the pan with Chem-Dip until the level reached about midway up the carbs. I then left it to soak for a half-hour to an hour. Keep in mind, NOT TO SUBMERGE THE DIAPHRAGMS!
The reason for the pan was, besides not wanting to screw around with any of the linkage and carefully set synchronization and place in the entire unit, was to make sure that the level of the Chem-Dip bath would NOT wash up onto the diaphragms. Take care to put the carbs in, and out of the bucket SLOWLY!! You do NOT want it to splash up onto the diaphragms, lest you run the risk of this miracle stuff to chew through the fragile rubber.
Before I got the Chem-Dip I spent a lot of money and time on cleaning supplies and tore into the carbs. The needles were a light yellow-brass color, and had deposits of nasty gas all over them. I carefully removed them and cleaned them down with brake cleaner (which was an awful idea, in hindsight), and by the time I was finished, the carbs LOOKED very clean and smooth. When I didn't have any success when mounted back on the bike, I went to the Chem-Dip bath, and learned the needle was actually SILVER in color!! Put them back on the bike, and WHAMMO! Started right up like she hadn't been sitting for 3 years!
Some concern was raised by even the FUMES of cleaning chemicals eating the diaphragms. Well, it worked for me, and I only let them sit in the pan for an hour at most, and I'll swear by my personal experience, but that doesn't mean someone can't get themselves into trouble with this stuff. It's VERY effective at stripping anything off metals. Including softer metals, if I read the label correctly. So you actually DON'T want this stuff on anything for too long
.
I hope this answers your question, Bladerunner. I think dipping is a great idea if you're careful and patient, even if the bike seems to be running well now, you may unlock an extra 5-10 horsepower!! WHO KNOWS?! And as I stated, all the stuff you would need to clean are on the bottom half, and all I took off was the bowl to allow the Chem-Dip to get at all the goods. I did submerge the bowls completely by themselves as well.
Let us know your feelings and results
