Author Topic: Are these Carbs done for? (Read 5204 times)

Accorn · « **on:** January 22, 2012, 05:53:04 PM »

I took my carbs off and found some surprising things in the float bowls. I noticed that there wasn't just varnish in them but there was also a white crusty build up. However on further inspection it appears that the white stuff was the result of the carburetor housing corroding from the inside out. One of the pictures below shows all the crap that fell out of them when I took the bowls off. The valve stems are eaten down and one of them even broke off at the top. I soaked the whole thing in simple green hoping to clean it up but no luck.

same thing happned in the petcock too.

I was hoping to restore this bike and get it running after a previous owner neglected it, but I think the carbs have to be scrapped. What do you all think? Is this from water in the gas?

nccb · « **Reply #1 on:** January 22, 2012, 05:57:32 PM »

good god, i thought the ones i was working on were bad

72500john · « **Reply #2 on:** January 22, 2012, 06:01:45 PM »

clean up what you got and see what can be salvaged...good god man those are bad. sorry to poop on your parade. looks like a bad case of intergranular corrosion.

MoMo · « **Reply #3 on:** January 22, 2012, 06:05:00 PM »

Look like the Slime That Swallowed The Honda Carb

If the metal is eaten, as it appears to be, you most likely will be looking for new carbs. One of the worst I've seen

Good luck with the repair...Larry

Post under the bikes and parts wanted, maybe someone has a set. Before you put anymore money into the bike check compression and do a leak down test if you have the capability...Larry

cb550choppa · « **Reply #4 on:** January 22, 2012, 06:09:40 PM »

ill give you 5 bucks for the jet clips

Accorn · « **Reply #5 on:** January 22, 2012, 06:11:35 PM »

I new something was bad when I pulled the bowl off and out came a pile of dust. And the fact that the top of the tower snapped off. Craigslist strikes again. The owner I bought it from sad it was running fine until he put bad gas in it and let it sit around for two years outside. I was hoping i could rescue it.

Do you think that this crap could have gotten in the engine? I didn't see any white stuff in the intake manifolds.

Accorn · « **Reply #6 on:** January 22, 2012, 06:15:52 PM »

Sorry I don't know what the "jet clips" are

lone*X · « **Reply #7 on:** January 22, 2012, 06:26:10 PM »

They are the bow shaped springs like the one in your middle picture. Hang onto all your parts until you get a good set of carbs cleaned and working. Never know what pieces may be missing from a replacement rack.

fmctm1sw · « **Reply #8 on:** January 22, 2012, 07:42:54 PM »

Those are as bad, if not worse, as the ones off my 550.

faux fiddy · « **Reply #9 on:** January 22, 2012, 07:43:50 PM »

Quote from: lone*X on January 22, 2012, 06:26:10 PM

. Hang onto all your parts until you get a good set of carbs cleaned and working. Never know what pieces may be missing from a replacement rack.

+1 They're probably junk, but they aren't garbage yet.

cmonSTART · « **Reply #10 on:** January 22, 2012, 07:48:49 PM »

Wow. Those are really bad.

dave500 · « **Reply #11 on:** January 22, 2012, 08:29:16 PM »

stalactites and stalagmites normally take thousands and thousands of years to form but it can be done in a few years in carbs.

Stev-o · « **Reply #12 on:** January 22, 2012, 09:00:19 PM »

Get new carbs, you should be able to find a rack for $100 or less.

messeduptriple · « **Reply #13 on:** January 22, 2012, 10:26:11 PM »

Quote from: nccb on January 22, 2012, 05:57:32 PM

good god, i thought the ones i was working on were bad

wow...me 2

Sent from my PC36100 using Tapatalk

grasscutter · « **Reply #14 on:** January 23, 2012, 01:18:44 PM »

And just think how long it takes to open the drain screws @ bottom of each bowl?

10sec total?

*shakes head*

Tugboat · « **Reply #15 on:** January 23, 2012, 01:27:29 PM »

Those leaf springs are impossible to find. HANG ON TO THEM!!

lucky · « **Reply #16 on:** January 24, 2012, 01:26:23 AM »

Clean them up THEN make a decision.
That white powder is aluminum chlorates. It is from dissimilar corrosion
between the brass parts and the aluminum.
The brass is more noble than the aluminum so the aluminum is wasting away.
They may still be salvageable and many parts may be salvageable.
Clean all of the parts FIRST and then decide what is useable.

When I look at the enlarged version of the photos they all look like they are salvageable.

davis96 · « **Reply #17 on:** January 24, 2012, 09:34:17 AM »

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:

Tugboat · « **Reply #18 on:** January 24, 2012, 09:57:32 AM »

^Wow! Nice!

grcamna2 · « **Reply #19 on:** January 24, 2012, 10:40:44 AM »

Welcome

to the forum Accorn !

Blow 'em off and scrape off the loose stuff as much as you can,spray them down w/ PBBlaster...,disassemble them, put in an ultrasonic cleaner and see what's left to salvage.I think it's a good thing to pay special attention to how the jets and other brass pieces "slip-fit" into their respective holes in the aluminum carb bodies...if those "slip-fit" holes where the brass jets w/ o-rings fit into are badly corroded inside those little aluminum "bores" in the carb bodies..well,they wouldn't seal very well any more. I'm sure you'll be able to salvage a great number of things

.

I wouldn't throw in the towel on those carbs(as lucky suggested

)until you've cleaned 'em up.

nccb · « **Reply #20 on:** January 24, 2012, 03:11:04 PM »

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

cb550choppa · « **Reply #21 on:** January 24, 2012, 03:16:29 PM »

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

fastbroshi · « **Reply #22 on:** January 25, 2012, 02:16:44 AM »

Quote from: davis96 on January 24, 2012, 09:34:17 AM

What mixture is this you used to clean them??

Scott S · « **Reply #23 on:** January 25, 2012, 05:17:45 AM »

Quote from: davis96 on January 24, 2012, 09:34:17 AM

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?

ADW · « **Reply #24 on:** January 25, 2012, 07:46:02 AM »

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........

lucky · « **Reply #25 on:** January 25, 2012, 08:12:27 AM »

Quote from: cb550choppa on January 24, 2012, 03:16:29 PM

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 · « **Reply #26 on:** January 25, 2012, 08:20:38 PM »

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

ADW · « **Reply #27 on:** January 26, 2012, 06:05:02 AM »

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 · « **Reply #28 on:** March 05, 2012, 04:56:51 PM »

Quote from: nccb on January 24, 2012, 03:11:04 PM

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

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

Quote from: fastbroshi on January 25, 2012, 02:16:44 AM

Quote from: davis96 on January 24, 2012, 09:34:17 AM

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

Quote from: Scott S on January 25, 2012, 05:17:45 AM

Quote from: davis96 on January 24, 2012, 09:34:17 AM
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.

Quote from: ADW on January 25, 2012, 07:46:02 AM

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).

Quote from: cb550choppa on January 24, 2012, 03:16:29 PM

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 · « **Reply #29 on:** March 05, 2012, 05:16:04 PM »

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 · « **Reply #30 on:** March 06, 2012, 08:54:08 AM »

Quote from: davis96 on March 05, 2012, 04:56:51 PM

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 · « **Reply #31 on:** March 06, 2012, 09:02:36 AM »

Quote from: wedoo2 on March 05, 2012, 05:16:04 PM

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 · « **Reply #32 on:** March 06, 2012, 01:00:48 PM »

that coil spring method is simply brilliant.

TwoTired · « **Reply #33 on:** March 06, 2012, 02:10:10 PM »

Quote from: davis96 on March 05, 2012, 04:56:51 PM

Quote from: ADW on January 25, 2012, 07:46:02 AM
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 · « **Reply #34 on:** March 06, 2012, 06:12:41 PM »

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 · « **Reply #35 on:** March 19, 2012, 05:56:38 PM »

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 · « **Reply #36 on:** March 19, 2012, 06:00:52 PM »

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 · « **Reply #37 on:** March 19, 2012, 08:23:37 PM »

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

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Author Topic: Are these Carbs done for? (Read 5204 times)

72500john