Topic: Checking float valve.. the unfun way?

[NGL_BrSH]

Ok, I have narrowed my woes down to the fact that the bowl is getting too much fuel and overflowing making my idle very rich.

1975 CB550K1, 022A carbs

I rebuilt the carbs for the 2nd time last night (must faster this time) and for giggles blew air through the vent hoses and found that they were ALL clogged with spider crap and bugs.

I inspected the condition of the float valves and they were not sticking or clogged.

Upon reassembly and reinstallation I found that at least one of the carbs is leaking fuel out it's drain tube..

I want to check function of the float valves.
Here's my idea.. please correct me if i'm wrong.
I'm going to remove the carbs again..   hook fuel up to them, remove one carb bowl... push the float up with my finger and turn the fuel back on.  This should verify if the valve is leaking I believe.
The valve kits are about 30 bucks each from hondaparts-direct and I don't want to start throwing more money at it if I can help it.
I measured the float height again and its absolutely perfect.. all 22mm's.

I'm really losing my mind here.  To boot while i was running it a new random ticking noise is coming the valvetrain somewhere.

[pdxPope]

Well, it is a little unorthodox, but that would tell you if the float valve assembly was doing it's job.

Why not just stick a piece of clear tubing in the bowl drain hole, angle it above the carb bodies and watch to see when / if it ever stops filling up?

-JP

[speedy gonzalais]

my 650 deos that on and off sumtimes it over flows and others it dont i have replaced the float valves and it still does it even adjusted the floats sumtimes gunk does build up and make them stick try an inline filter if u aint got one allready also the clicking might be the tappets need readjusting or one of the ht caps may be knackard

[NGL_BrSH]

Well, it is a little unorthodox, but that would tell you if the float valve assembly was doing it's job.

Why not just stick a piece of clear tubing in the bowl drain hole, angle it above the carb bodies and watch to see when / if it ever stops filling up?

-JP

I had thought of that and intended to use my 5mm tubes for my carb sync but was sadly dissapointed to find that the holes are larger.  Perhaps i'll just hold it wiht pressure in the hole and a tapered vacuum fitting.  Thanks for the help.

[Bob Wessner]

Well, it is a little unorthodox, but that would tell you if the float valve assembly was doing it's job.

Why not just stick a piece of clear tubing in the bowl drain hole, angle it above the carb bodies and watch to see when / if it ever stops filling up?

-JP

I had thought of that and intended to use my 5mm tubes for my carb sync but was sadly dissapointed to find that the holes are larger.  Perhaps i'll just hold it wiht pressure in the hole and a tapered vacuum fitting.  Thanks for the help.

There was a posting not long ago whereby the member took some clear tubing slightly larger than the hole and heated carefully and then pulled it so that it reduced the diameter in the heated portion. He then cut it along the tapered part and 'screwed' the tapered part into the hole. This may not be very descriptive. I'll try to find it.

[750K2]

there's also the possibility that one of the overflow tubes is cracked.  there's  a couple of fixes on this site.  good luck

[Bob Wessner]

Found it, if this helps...

http://forums.sohc4.net/index.php?topic=37851.msg390105#msg390105

[NGL_BrSH]

thanks brotha.. i'm all over that tonight when I get home.

upon inspection of the overflow tubes they look great as did the float height.. I think i'm due for new float valve seat and valve.

It's been spilling back into the air filter a little.. washing out my new foam filter pretty bad.

So it can't be the overflow tubes.. its def float height or shutoff valves.  It's make it run rich.  Hopefully i just need to bend up the float tabs a tiny bit and i'll be good to go.  I JUST WANT TO RIDE.

[manjisann]

I know sometimes you can find just the float needle and seat for a decent price, I think Dennis Kirk carries them like that. Bear in mind that over time the spring that keeps the little pin part of the needle against the float tab will weaken and slowly allow the level to rise. I was very surprised how much stiffer the new needle springs were on the new ones versus the old ones. It may be worth it for peace of mind just to replace all 4 of them. I was having issues with 1&2, and after the 3rd time taking them off, I went ahead and just replaced 3&4 so I won't have to worry about it.

I JUST WANT TO RIDE.

I hear ya, believe me I hear ya. But you definately don't want that liquid gold leaking out all over the road, or worse your hot engine.

Good luck

Brandon

[jtb]

I had the same problem early on with  my 750F, number one carb.  Turned out to be a crack in the casting, where the drain screw seats.  $51.00 and a new #1 float bowl, problem solved.

[NGL_BrSH]

ugh..

well i check fuel height.. all of them looked the same as pic below.. fuel up to the barrel of the carb.  I must have installed the floats upside down?  I reinstalled them the same way they came out.  The PO to my dad said they couldn't get it to idle right.  HMM.
Strange though because it doesn't pour out.. or even really come out after a while, only if i move it around or run it for a bit.

Looks like I have another carb pull! weee.  At least now I have some hope to fixing this bastid.

gosh I hope the floats are upside down and I just flip them and everything is perfect!

I called my dad (veteran mechanic) and said.. "I think that I figured out why it's running rich.."

He says "Because you're getting too much fuel?"

"ha.....ha" I reply.


edit: can someone show me the proper orientation of the floats for a 022a carb please?  I'm currently searching but i'm not finding much and fiche doesn't help.

[MrZxp]

This is all the shop manual shows....

[oldbiker]

It's worth remembering that sometimes the pivot pin can be worn so that the float does not move freely.

[NGL_BrSH]

Does anyone here have any idea where the fuel level is supposed to be?

I know the floats are supposed to be 22mm  and i KNOW for a fact that they are (maybe upside down but regardless 22) but where is the fuel level normally sit?

[TwoTired]

Try about 1/4 inch below the gasket mating surface of the float bowl.

[NGL_BrSH]

Thanks TT, I was hoping you would reply.  So what to do now is really the question.  I remember checking the floats to see if they had leaks by submerging them overnight and they floated as soon as i let them up with nothing inside.

If they are not upside-down (which after looking at the pics, I'm 99% sure I oriented them right) what would your next step be?

I can only find those valve seat and float needle sets for 20 bucks EACH on hondaparts-direct.. after shipping it's $90  UGH.  So I would hate to throw parts at it that it doesn't need.  Think this is it?  I was thinking I could alter the float height to perhaps compensate for fuel height?

[Frankenkit]

Z1 enterprises has the float needles in a 6 pack for $21.... not sure about the seats, though... and I'm considering those, too.

[TwoTired]

I'm thinking you (or someone) adjusted them wrong.

Each float valve has a small spring pin at the end which rests on a tab which is part of the float pivot.

I'm guessing that someone adjusted the float height with that pin fully compressed, which is wrong.
That small pin on the valve should be fully extended and the valve on the seat when the tab makes contact and the height is measured.
The tab is then bent to achieve this orientation at the measured float hight.

The problem with this theory is that this error should have the fuel level too low.

Or...
Did you remove the float seats from the carb bodies?  They seal with orings.  Did you replace these?  Could they be damaged and allowing fuel to bypass the float needles?

Or...
Have the float needles been put in backwards?

I'm guessing you've got some kind of assembly error, that you can't see as obvious, since you got them that way.  Especially since all four are behaving the same way.

The float system is a fairly simple mechanism, that, with some thought and observance, can be easy to understand the principles of operation.
There's a fuel supply on the inlet of the valve.  When the fuel level rises, so does the float and it closes the valve, stopping fuel entry.  When the fuel level falls, the valve opens again to let fuel in.  (Your toilet cistern has the same type of fill principle, btw.)

Take it apart, observe, adjust, and make it work like it should.

Or, take some pictures so we can see WTF.

Cheers,

[NGL_BrSH]

well I was talking to my mechanic.. better known as dad and he's very conservative as far as spending money *cheap* and said just bend the tabs up and see how it goes..

instead I just manned up and spent the 50 bucks at Z1 for the 4 float seats/valves.  I think this should about do it.  I have a good feeling the spring much weaker than original and the new ones should fix my problem.  Also since the floats measure a perfect 22mm.. why mess with that.

[manjisann]

Just on the off chance it doesn't work, you can take a pick of how it is being put together. I suppose it's not impossible, especially if the po had put them in upside down, but the float needle has a pointy end kinda like and old style plumb bob, and the bottom has a pin that goes in the needle body and back out again due to the spring. Also, if the tops of the needles have worn due to the normal repetition of the float moving up and down and forcing the needle against the seat, that could allow fuel to slowly seep into the carb bowls.

well I was talking to my mechanic.. better known as dad and he's very conservative as far as spending money *cheap*

Probably not cheap, just frugal, and that isn't a bad thing  But it is nice to know that the part you have won't fail you at the wrong time. If your carbs are the ones like mine (which it looks like from the photos) You take the bowl off, take the floats off, unscrew the seat holder thingy (is that a legit technical term??) and gently pull the old seat out with a pair of pliers. Inspect the seat area just to be sure all is good, maybe spray with some carb cleaner and press the new seats in and reassemble in reverse order. Be sure when putting the bowls back on that the gasket stays in the grooves. For some reason the ones I had seem to be ever so slightly too big for mine and kept wanting to fall out. I didn't notice one had done that and it eventually started leaking and I had to replace it cause the bowl had cut it in two. I don't know if I will be shot for suggesting it, but I used a very small amount of gasket sealer I have lying around and put it in the grooves to hold the gasket in place. If you do this, just be sure that none of it is on the inner side of the gasket, because if it gets into your bowl, it could plug up your jets.

Hope this is of some use.

Brandon

[NGL_BrSH]

well.. I'll definitely be very careful to properly assemble them again.. I do remember 22mm with the needle valve with pointy side up and just touching the tab.  I just think that the springs are very tired.  Maybe small rust spot or osmething.. this thing sat for about 17 years.

So I figure new valveseats and springs can't hurt.

I do remember reading some post of TT's saying he puts some grease or something on the orings to make them go together easier during reassembly but I can't remember what that was and I can't find that post again.. any recommendations?

Thanks for all the help so far from everyone, it's greatly appreciated and I can never get enough suggestions.

[mystic_1]

I do remember 22mm with the needle valve with pointy side up and just touching the tab.  I just think that the springs are very tired. 

Erk, not to be pedantic or anything, but you mean "pointy side up and the other side with the spring-loaded pin just touching the tab", yes?  The pointy side of the float needle goes first into the seat, the other end touches the float.


mystic_1

[NGL_BrSH]

yup, thats how they all are.  pins down, points up.  just touching the tab when i measure it

[Frankenkit]

Not to completely hijack or anything, but do mechanical carbs have this seat, too?  From what I see (though maybe I'm not looking far enough inside) it just looks like my needles seat against a brass base?

[mystic_1]

The brass base IS the seat   It unscrews from the carb body.  The end of the hole in the brass piece is machined to match the taper on the end of the needle.

mystic_1