Topic: cb550 still fouling plugs

[78whiteorbs]

As others have mentioned:

 Yes, the tubes need to be vented to the atmosphere, nit linked together.

 The carbs should be on their sides, slightly tilted back, with the weight of the floats just touching when setting float height.

 The emulsion tubes should be pulled, but they effect more mid-range operation. It might feel sluggish or run a little rich, but that shouldn't foul the plugs in such a short time like you're experiencing.

 You mentioned earlier in the thread about having not adjusted the valves. Did you ever do that? Have you use a vacuum gauge to sync the carbs?

Scott the floats are set perfect. I do know how to measure float height having over 100 bikes in the past 2 or three years(plenty of practice and only one other set of carbs have given me trouble in the past so I feel pretty sure of my competence in seeing float height). These are especially easy as when the carb body is on its side when the tang barely just touches there is no compression of the valve spring like on older needle valves as these are brand new and very stiff.

I will open that vent tube but there were four others that weren't plugged in operation.

If the emulsion tubes are extremely clogged then in midrange "on the needle"  it would not have the air necessary to atomizer fuel and could be fouling g me out. It does feel like that would be too fast to foul like you said though but a man can dream a little huh?llol
The orings in the manifolds are very supple as new and are sealing perfect. I even went to the extent of using a super light coating of seals all there.

I do have a Morgan carb tune and have synced carbs but bud you are calling me out I indeed have not adjusted valves yet.... II know I know shame on me. I know you are suppose to adjust valves before vacuum syncing. To much gas is the problem somehow somewhere I feel . When I turn the gas off it runs fine. Terribly frustrating with such nice weather. ..:-(

[Scott S]

  I wasn't saying you don't know how to set floats, just reiterating what was mentioned.

 The four tubes on the bowls aren't really vents. They're overflow tubes. If the two vents are crossed over, that's similar to having a gas cap that doesn't vent or whatever. The atmospheric pressure  on those two vents helps keep the fuel level at the right height. It *could* be something as simple as the fuel not being able to find it's level. Snip that tube or remove it. See what happens.

 If that cures it, install two ~10 inch long tubes that vent down towards the back of the bike. Just to keep out dirt and get them in "still" air.

[78whiteorbs]

  I wasn't saying you don't know how to set floats, just reiterating what was mentioned.

 The four tubes on the bowls aren't really vents. They're overflow tubes. If the two vents are crossed over, that's similar to having a gas cap that doesn't vent or whatever. The atmospheric pressure  on those two vents helps keep the fuel level at the right height. It *could* be something as simple as the fuel not being able to find it's level. Snip that tube or remove it. See what happens.

 If that cures it, install two ~10 inch long tubes that vent down towards the back of the bike. Just to keep out dirt and get them in "still" air.

I will do that thanks for the input .

[78whiteorbs]

Removed the line joining the two vent tubes went for a ride and seems the same. After a short spell it starts fouling /flooding and if I turn the petcock of it clears up and runs fine. 

I disassembled the carbs again removing the needles and emulsion tubes which were actually quite clean. Was hoping for a smoking gun but nada. Cleaned everything up and am gonna video the reassembly for outside observation.

Question: are he mixture screws suppose to have orings?
Mine just have the springs.

[78whiteorbs]

I also polished the bore where the main jet and valve seat reside with a little steel wool cigar For good measure.

[harisuluv]

there are no orings on the mixture screws.

I don't know why you're making things so difficult for yourself.  You have a smoking gun already, you turn off the fuel and your problems clear up.  FUEL. IS. NOT. STOPPING.  You have a problem with your floats/float valves/float height.

I don't know if you've been paying attention, but i've been begging for pictures.  Commented about the float height being way off, and that it suggests your floats are tweaked to hell.  From the side.  Straight on.

Do not mix float seats and valves.  They are not interchangeable after having any wear.  This in itself could cause your problems. 

You don't need to disassemble the slide arm, just more work and will make it easier to lose something.  Work on the clues you have, not random tangents and directions.  Doing that leads to more of the same.

Your main jets look radically different in appearance, did you replace some and not others?  Why do some look very old and some new?

[78whiteorbs]

there are no orings on the mixture screws.

I don't know why you're making things so difficult for yourself.  You have a smoking gun already, you turn off the fuel and your problems clear up.  FUEL. IS. NOT. STOPPING.  You have a problem with your floats/float valves/float height.

I don't know if you've been paying attention, but i've been begging for pictures.  Commented about the float height being way off, and that it suggests your floats are tweaked to hell.  From the side.  Straight on.

Do not mix float seats and valves.  They are not interchangeable after having any wear.  This in itself could cause your problems. 

You don't need to disassemble the slide arm, just more work and will make it easier to lose something.  Work on the clues you have, not random tangents and directions.  Doing that leads to more of the same.

Your main jets look radically different in appearance, did you replace some and not others?  Why do some look very old and some new?

Thanks for the tough love there brother-

 I have cleaned and rebuilt dozens and dozens of carbs using the exact same procedure and method .Never had such an encounter as this, it defies logic for me. That is why it made since to me to look elsewhere after resetting the floats 3 times. The needle valves and seats are all brand new with zero wear short of the 2 10 minute rides(wwould that void there new status in wear) The carbs are not puking out the overflow vents. So in theory if THE. FUEL .IS. NOT.STOPPING why aren't the carbs overflowing. Furthermore when I test them by blowing air from my lungs the valves stop the airflow like they are suppose to where they are suppose to . Do you see how this might make a man cause to look in another area. Perhaps I am very well making this overly complicated but I assure you it is not by choice here,lool. I'd rather be riding than finding problems to pester myself with.I am no sadist.

The main jets , 3 are orginal  and one is newer reproduction . Like this when I got em. Numbers are all the same and they all are similar in size to the naked eye when compared to one another. What pictures specifically do you need to see? As I stated I will video the reassembly and float height setting .By all means please point out anything you see.

I Thank you for your input and do recognize your superior experience in relation. Perhaps I am  a compete idiot but in almost a hundred bikes at least half of which where sohc inline 4's I have never had this occur. Just  last week I rebuild a set of 350f carbs with all new brass and needles from 4 into 1 with not one issue afterwards.Not one .

[DaveBarbier]

Do you know for a fact that your overflow tubes aren't clogged? They'll only drain an overfilled bowl if they're clear.


---
1978 Honda CB550K

[harisuluv]

If it's flooding and not coming out the overflow then there is a problem in the brass drain in the bowl, or in the rubber drain tubes (if you have them on).

You cannot equate the pressure you apply yourself with your hand or whatever to the valve as being exactly equal to the force that is created from the float.

I'm interpreting the term "flooding" as flooding of gas.  If it's flooding then the delivery of gas is not stopping as it should be.

[78whiteorbs]

If it's flooding and not coming out the overflow then there is a problem in the brass drain in the bowl, or in the rubber drain tubes (if you have them on).

You cannot equate the pressure you apply yourself with your hand or whatever to the valve as being exactly equal to the force that is created from the float.

I'm interpreting the term "flooding" as flooding of gas.  If it's flooding then the delivery of gas is not stopping as it should be.

Yes I am certain the overflow Tubes are not clogged.

And this is why I am baffled. My reasoning behind stating it's flooding is simply because when I turn the petcock off it runs perfect.  So perhaps perhaps the plugs are fouling because of to much gas before reaching the level of overflow and if I were to leave the bike with petcock open after it stalled it would indeed overflow.

I if it's. As easy as yoU are making it sound it would be running properly by now I assure you And I wouldn't be posting such a rookie problem .IIt would be fixed. I know how to set float height and I know how to observe When a valve is Not working. There is something unusual here

[78whiteorbs]

Totally agree with this
You cannot equate the pressure you apply yourself with your hand or whatever to the valve as being exactly equal to the force that is created from the float.

[Scott S]

 I am sure you are capable of doing the carbs, but that picture of all the parts scattered everywhere gives me the heebie-jeebies!
 I like  to do them one at a time, or at least tag and bag everything so they don't get dropped on the floor and lost. Like that little pointed pill that that's held in behind a spring....I'd hate to lose one of those!

[DaveBarbier]

And I wouldn't be posting such a rookie problem .IIt would be fixed. I know how to set float height and I know how to observe When a valve is Not working. There is something unusual here

No offense, but you didn't know the procedure when to set tappet clearance (which is fine and what this forum is for) but you can't then go saying that you have a lot of knowledge and you're not a rookie and for us to "trust" that there's some crazy scenario happening. And without the pictures that Harrisuluv has been TRYING to get from you it's hard to diagnose. Why would we NOT start with something easy like drilled pilots, or valves not working properly when 9 times out of 10 that's the problem and the user is the one making it more complicated?

No one here knows you or what you're capable of. There's plenty of hot heads that have no idea what's going on that proclaim vast experience. Just allow us (or I should say them, because I don't have the experience the rest of the people do that are trying to help) to diagnose and run through the simple possible solutions first. Occam's razor.


---
1978 Honda CB550K

[ironrod60]

Just a suggestion that worked for me and maybe someone has already suggested it. I replaced the float bowl phillips with caps screws. It made it infinitely easier to remove the bowls while the carbs are still on the motorcycle.

[78whiteorbs]

Occam's razor

Don't know about you WOrbs, but I've tried that brand but always go back to Gillette myself. A close shave is a thing of beauty...

Just injecting a bit of levity lest we all get testy with each other.

thanks man,  occams razor- by the power of greyskull!

I appreciate all the input fellas. Don't mean to give you the newbie  jeebies Scott have seen the inside of your garage and you are a very neat and organized man. At times my shop has the mad scientist motif going on but I know exactly where everything is.  On an interesting side tangent for pure sharing of useless information: there was a study done about productivity in relations to organization in the work place. It was commonly thought that the people with the messiest desks  where the least productive and unorganized  and the ones with the perfect symmetrical layouts with each pencil sharpened and even number of turns where the most organized and the more productive(end of run on sentence).
This is an interesting article.http://m.mic.com/articles/103954/the-science-of-why-the-most-creative-people-have-the-messiest-desks
http://lifehacker.com/why-creative-geniuses-often-keep-a-messy-desk-1534885018

[78whiteorbs]

Just a suggestion that worked for me and maybe someone has already suggested it. I replaced the float bowl phillips with caps screws. It made it infinitely easier to remove the bowls while the carbs are still on the motorcycle.

Thanks man - use to do that but after running across a few carb racks where the float bowl holes were stripped from the stronger metal being over tighten I shy away from it unless I have to run a nut on the other side because t he y are stripped. thanks for the positive suggestion!

[Scott S]

 Newbie-jeebies...stupid auto correct. That's what get for trying to post from my phone. I was trying to say heebie-jeebies.

[78whiteorbs]

Hahahaha!

[DaveBarbier]

Newbie-jeebies...stupid auto correct. That's what get for trying to post from my phone. I was trying to say heebie-jeebies.

Haha, I thought you had made up some new lingo for the Internet. I kinda like it.


---
1978 Honda CB550K

[Stev-o]

Newbie-jeebies...stupid auto correct. That's what get for trying to post from my phone. I was trying to say heebie-jeebies.

Haha, I thought you had made up some new lingo for the Internet. I kinda like it.

+1

[DH]

Please don't flame me for this folks, just a stab at what might be a/ the problem.
If the fuel level in the bowl is too high, but not enough to overflow, could that affect the way the needle jet
vaporizes the fuel in a negative way, too rich? Also, the floats hanging up would be a good possibility to check for
as mentioned. Anyone have a safe way to do clear tube with engine running?

[mrfish2]

Hey Whiteorbs, I finally got the time to tinker with mine today. I got brand new float valves/float needles that ended up being Keyster brand, and after installing those in the bike and re-setting the fuel level the bike idles almost perfectly (still dealing with running pretty rich). I discovered I hadn't replaced two of the original float valves (for whatever reason, I'll never know), but maybe you could try replacing yours and see what happens?

[78whiteorbs]

I sold mine to Scott S. That fixed it :-)
Now back on my other cb750 and my rd400 project.

[Scott S]

Well, we'll see....

 I haven't done much other than order parts and do a little cleaning. I'm leaning towards an ignition issue. I'll go over the whole tune-up deal eventually and swap in a Pamco, new plugs, caps, etc., and Ohm out the coils. I'll report back if and when I find anything. Might be a while, though. I have three ongoing projects and work on whichever one seems most promising that particular day!