Topic: Are these Carbs done for?

[lucky]

i have a clean set of carbs missing jet clips but other wise complete ill sell cheap quick cleanin and ready to go

You can get those clips at any hardware store. They are snap ring clips.

[dave500]

umm?i think its a leaf type spring with an elongated hole that retains the type one jets.

[ADW]

I think Lucky is talking about the jet NEEDLE clips, whereas I think Dave500 is correct that the leaf spring main jet retainers are what the guy who had the carbs was saying he was missing. So I think the whole thing adds up to the OP has the missing leaf springs that the guy with the set of carbs was missing. So the OP will have all he needs if he keeps his leaf springs and buys the carb set. I think!

[davis96]

did you put the floats in that carb dunk too Davis96?

No, the floats were easy to just wipe down no worry about corrosion

What mixture is this you used to clean them??

If I remember correctly, that is lemon juice/vinegar/water/dish soap... It worked out ok, but honestly I think pine sol and regular ole carb cleaner is the way to go with these carbs

Don't give up on 'em just yet, unless you've got money to burn.
Here's the mess I inherited and the result after many hours of cleaning:

 Hard to believe those are the same carbs! Tell me about the screens? How did you attach them inside the stock velocity stacks?

The screens are just window screen, cut to size and expoxied to the side of the factory stack which faces the carb mouth.

Am confused/concerned about the vent line "U turn" in the center of the stack in the photo of the clean/reassembled stack. Those two are the atmospheric vent lines on my CB350F carbs. They're spodabe two separate long vent tubes that end up hanging down behind the engine near the swingarm like the overflow lines do.

Is this carb set different for some reason? The way it's set up now the bowls will never fill with fuel because there's no outside venting to relieve the suction that will occur when the bowls begin to fill. Unless these are different and I'm missing something. These do appear to have 2 fuel feed lines (my 350F only has one) so maybe it's correct this way........

There has been some debate on this topic before, because I have seen the two center vent lines connected as I have done and open to atmospheric pressure as you've described. I think the purpose of the lines between the carbs might be to sort of equalize pressure between the carbs, rather than to vent them (I think there are other ways the carbs are vented like the air screws?). I ended up being swayed by the opinions of some of the members here and removed the "U" shaped line altogether... that said, the way I had them set up in the photo did actually work just fine and I had no problem with fuel not getting to the carbs (quite the opposite, actually, the carbs had float level issues and pissed gas like nobody's business).

i have a clean set of carbs missing jet clips but other wise complete ill sell cheap quick cleanin and ready to go

If this doesn't work, I devised a way to eliminate these stupid leaf springs altogether, as they are apparently made of unobtanium and have a tendency of disappearing:

Here's the thread in the FAQs:
http://forums.sohc4.net/index.php?topic=101803.0

[wedoo2]

I'm glad you asked the question and posted the picture, because if it had been me I would have closed them back up and start looking again.  Davis96 gives you some hope.  But, that was some bad gas the PO put in there.

[gnarlycharlie4u]

If I remember correctly, that is lemon juice/vinegar/water/dish soap... It worked out ok, but honestly I think pine sol and regular ole carb cleaner is the way to go with these carbs

Careful about using vinegar on those carbs, you want to make sure it's at least a 50/50 mix of water and vinegar as the vinegar reacts with aluminum and can eat (etch) the bodies.
That being said, aluminum is awesome for getting rid of aluminum oxide; that white stuff in OP's pic.

My preferred method of cleaning carbs is definitely Simple Green + water in the ultrasonic cleaner. Pine-sol is good too but that can sometimes damage or stain metals.

[davis96]

I'm glad you asked the question and posted the picture, because if it had been me I would have closed them back up and start looking again.  Davis96 gives you some hope.  But, that was some bad gas the PO put in there.

Bad gas would be a better alternative, the stuff in your carbs is the same stuff that was in mine, corrosion caused by water sitting in the float bowls. In the interest of full disclosure, the pic of the clean carb body I posted was the cleanest of all mine with the least corrosion. The ones that had a lot of water in em were corroded to the point where they almost looked unusable (there was severe pitting, almost 1/4" deep in a lot of places). But still don't lose hope, after cleaning all the white corrosion out, the carbs work just fine, despite the heavily corroded metal.

[dave500]

that coil spring method is simply brilliant.

[TwoTired]

Am confused/concerned about the vent line "U turn" in the center of the stack in the photo of the clean/reassembled stack. Those two are the atmospheric vent lines on my CB350F carbs. They're spodabe two separate long vent tubes that end up hanging down behind the engine near the swingarm like the overflow lines do.

Is this carb set different for some reason? The way it's set up now the bowls will never fill with fuel because there's no outside venting to relieve the suction that will occur when the bowls begin to fill. Unless these are different and I'm missing something. These do appear to have 2 fuel feed lines (my 350F only has one) so maybe it's correct this way........

There has been some debate on this topic before, because I have seen the two center vent lines connected as I have done and open to atmospheric pressure as you've described. I think the purpose of the lines between the carbs might be to sort of equalize pressure between the carbs, rather than to vent them (I think there are other ways the carbs are vented like the air screws?). I ended up being swayed by the opinions of some of the members here and removed the "U" shaped line altogether... that said, the way I have them set up did actually work just fine and I had no problem with fuel not getting to the carbs (quite the opposite, actually, the carbs had float level issues and pissed gas like nobody's business).

The fuel in the bowls must have a source of atmospheric pressure to push fuel through the fuel jets into the carb throats (where there is reduced pressure supplied by the engine piston falling).

The dedicated vent nipples for this purpose are the fittings where the "U" hose is connected and defeats it's intended purpose.

The alternative source of atmospheric pressure that allows the carbs to work despite the vent defeat, is from the carb bowl stand pipes and their drain tubes.  When the carbs aren't overflowing these tubes are clear to equalize pressure above the fuel level in the bowls.  If those hoses get plugged for any reason (must all be blocked) the carbs with cease to function.  And bowl filling from the fuel supply will become problematic.

I have seen all the vent/drain line hoses blocked with insect nests/mud.  But, that bike had been sitting outside more than a year.

FYI: There is one version of CB750 PD carb that has no separate/dedicated vent hose.  These do have top of the bowl chamber interconnect channels among the four carbs, and "venting" or the atmospheric pressure source is the four bowl standpipes and drain tubes.

Cheers,

[Lostboy Steve]

Those really don't look all that bad. Mine looked like someone cured them in shellac for 20 years and then rolled them around in some mud and they came out great.

[Accorn]

I'm finally back, and now found some time to work on it. I had the carbs checked out by someone with more carb sense than me and they said i need new ones. Anyone know of a good place to get some new carbs? Can the CB550 carbs fit?

[harisuluv]

I think you are right you are better off finding a better set to start with.  Look on ebay and don't buy the first set you see, you need to be discriminating as many sellers will "forget" to mention things like the slides being stuck.  Ask questions if they don't list it in the auction page and always ask about what it looks like inside the floats.

[Doggie]

What bike do theses carbs fit? I have some extra sets on the shelf.
E-mail me at dht4343@aol.com. See if I can help you.
                                                        Doug