Topic: Stuck Float?

[essbee]

Got my new project started for the first time yesterday, a '76 550. Ran pretty well considering it hadn't been started in two years and no storage maintenance had been done prior to the mothballing - however - it was spitting gas from one of the carb overflow tubes, so I'm assuming that the float is stuck. What's to do?

[Mekun]

Time for a carb clean.  I cleaned my carbs and one started to stick after 3 months pulled the bowl and removed the float valve and seat. There was a big booger holding the valve open. I did it all with out pulling the carb bank.

[JS550]

My 76 550 did the same thing. Clean up the carbs & jets & run some seafoam through it when you fill up is what I was told.

[Inkscars]

Sounds like I can't say anything that hasn't already been said. Just went through this a couple weeks ago on my own. Think of it this way, at least it's not all 4 like mine.
You'll have it fixed in no time. Just make sure you set them right the first time. I was cussing the second time I had to pull em off.

[Righteous Wallace]

Hey guys, don't mean to hijack the thread, but i'm new here and i've got the same problem on a CB350 i just picked up. Can someone direct me to the right path as to what i need and need to do to clean the carbs? I can take the carb off and take the bowl out and everything, just don't know what all is needed to clean the carb and get it to stop leaking fuel. Or should i just replace the float? If so, is there a kit i need to buy?
I'm new to bikes and this is my first bike, so be easy on me guys 

Thanks,
Wali

[Johnie]

Hey guys, don't mean to hijack the thread, but i'm new here and i've got the same problem on a CB350 i just picked up. Can someone direct me to the right path as to what i need and need to do to clean the carbs? I can take the carb off and take the bowl out and everything, just don't know what all is needed to clean the carb and get it to stop leaking fuel. Or should i just replace the float? If so, is there a kit i need to buy?
I'm new to bikes and this is my first bike, so be easy on me guys 

Thanks,
Wali

A good start is to get a Honda service manual.  Then some carb cleaner to soak them in if you are planning to completely rebuild them.  I am not familiar with the CB350, but I know on my 400 I can just drop the float bowls and all the jets are there easy to remove.  If you do it that way get some carb spray cleaner and clean the jets and use air to blow them out.  You should not have to replace the float unless it is like my KO that had a leaking brass float.  You may need to replace or at least clean the needle and needle seat that will fall off when you remove the float itself.  Not a bad idea to check the float height too.  This is just a sampling of what you can do for starters.  Check the SOHC FAQ area for more info and good luck with it.  Below are a couple pics of what you may find when you take the float bowl off.

[Righteous Wallace]

Thanks for the reply!

Should i just download the service manual? I noticed earlier that all the service manuals in the FAQ are for four cylinder 350s, i have a twin, unless they are the same for the most part.

And as far as the float, i took the bowl out and inspected the float, and it seems fine. But it still leaks from the overflow pin. I guess it just needs to be cleaned? Would i have to take all the needles apart as well to clean the carb? I'm afraid once i do that i won't know where what goes. But i guess that's where the manual will come in handy.

Would i be able to find carb cleaner at a local auto parts store like Advance Auto Parts or something? No i'm not trying to rebuild them, not for now at least. Just want to get it to stop leaking and want to be able to ride the bike. And how do i check the heigh of the float?

Thanks.

[Johnie]

Sure...just download the manual.  I think they are pretty much the same.

If it still overflows it could be dirt in the needle and seat, or they are worn and need replacement.  If the float height is wrong that could also cause it to overflow.  And if the brass float drain pipe in the center of the bowl is cracked you will have the leaking too.

Many guys use a camera when disassembling any bikes.  Those digital pics come in handy when putting it back together. 

Yes, you can find carb cleaner at any auto store.  I usually buy it in a spray can if I am just doing a minimal clean of the jets.

Float height can be checked while some carbs are on the bike.  It depends on the clearance you have under there with the float bowl off.  Use your manual to find out the millimeter for the float.  I made a tool for my 750's and attached a pic for you.  It is easier to set the float with the carbs on their side.  The service manual says to check the float height when the float just touches the tip of the needle.  So it is a bit harder to do with the carbs on, but half the fun is figuring out how to do it on your own.  You could just leave them as is and see how it runs once you get the leak repaired.

[Righteous Wallace]

Ok, thank you!

I'll take the float off and recheck it for cracks or fuel inside when i get a chance. I'll try to figure out how to measure the height as well. If worse comes to worst, do you happen to know a site where i could just order a float or a needle and seat?

Oh and to clean the needle and seat, can i just take that phillips screw off and let the needle drop? And then stick it back in and tighten the screw? That won't hurt anything?

[Johnie]

Ok, thank you!

I'll take the float off and recheck it for cracks or fuel inside when i get a chance. I'll try to figure out how to measure the height as well. If worse comes to worst, do you happen to know a site where i could just order a float or a needle and seat?

Oh and to clean the needle and seat, can i just take that phillips screw off and let the needle drop? And then stick it back in and tighten the screw? That won't hurt anything?

Just go to your Honda dealer and they will order it for you.  There is also www.hondadirect.com  Go to the forum site here called "Good Folks" and that lists some quality vendors.  There is also www.westernhillshonda.com in OH that many of us like too.

As far as the phillips screw I do not know what set-up you have.  On my 400 all I do is push the bar out that holds the float.  Then the float and needle jet will drop out.  Never heard of a screw holding the needle jet or float.  You might be talking about the needle seat which is threaded into the underside of the carb body.  The needle jet will fall out of there.  Then you just lightly push the new one in and hold it in place while you install the float back in.  Just take your time and watch how it comes apart.  You may want to wait until you have the parts before take it apart.

[BeSeeingYou]

If you have those copper floats check them for leaks or almost invisible hairline cracks.  My XS650 has these and they developed these cracks from age I assume and allowed gas to get inside and sink them causing the same problem.  I soldered up the cracks and continued to use them until I could get new ones.

[Righteous Wallace]

Just go to your Honda dealer and they will order it for you.  There is also www.hondadirect.com  Go to the forum site here called "Good Folks" and that lists some quality vendors.  There is also www.westernhillshonda.com in OH that many of us like too.

As far as the phillips screw I do not know what set-up you have.  On my 400 all I do is push the bar out that holds the float.  Then the float and needle jet will drop out.  Never heard of a screw holding the needle jet or float.  You might be talking about the needle seat which is threaded into the underside of the carb body.  The needle jet will fall out of there.  Then you just lightly push the new one in and hold it in place while you install the float back in.  Just take your time and watch how it comes apart.  You may want to wait until you have the parts before take it apart.

Yea i apologize, i was thinking of something else. I believe i know what you are talking about now! And thank you for the links!

If you have those copper floats check them for leaks or almost invisible hairline cracks.  My XS650 has these and they developed these cracks from age I assume and allowed gas to get inside and sink them causing the same problem.  I soldered up the cracks and continued to use them until I could get new ones.

Alright. Thank you!

[Righteous Wallace]

So i took the float out and shook it by my ear, and it's definitely got a good amount of fuel in it 

Can i just buy the float or do i have to buy a full kit or something? I'm gonna need the gasket too of course.

[Righteous Wallace]

Ok i found the part. Can someone tell me which Honda Code # is the bowl gasket? All the gaskets are marked 3.

[Johnie]

When I was at my dealer it was like $18 each for the float needle and seat.  It was only a few more bucks to get the whole kit gaskets and all.  Do you have a Honda dealer near you?  I do not know if the brass floats are still around or not.  I know you can get them at www.yamiya.com  That site is in Japan and these people are committed to the early 750's.  They have quality parts and shipping is faster than in the USA.  I have bought a lot of parts from them.  But I did check the site and they have the brass bowl.

[Righteous Wallace]

Hmmm, didn't think dealers still had old motorcycle parts. You're talking about a normal Honda dealer correct? And yea i believe there is one about 10 mins away from me. I'll double check.

And that site, is it for 750s only?

[Johnie]

Never hurts to check your dealer.  You car correct, that yamiya site is mainly for the 750.  But you can always check www.westernhillshonda.com in Ohio.  They have a lot of vintage parts.

[Righteous Wallace]

Well as far as ordering online, i'm ok with ordering from the site i posted a pic of above, which is one of the sites mentioned in the FAQ here. But i'll call the dealer today just to make sure.

[Johnie]

Well as far as ordering online, i'm ok with ordering from the site i posted a pic of above, which is one of the sites mentioned in the FAQ here. But i'll call the dealer today just to make sure.

Dealer probably will not have in stock, but may be able to order it.  I stay in pretty good contact with my dealer and they give me a discount because I buy a lot of parts from them.  Good luck with your project.

[Righteous Wallace]

Yea i called the dealer and they said i would have to call a local motorsports store. Called one up and they can get it for 26 bucks, and 13 bucks for the gasket set. And they can have it in about 3-4 days. Not bad since some of the websites can't get it to me for less than 9 days and still charge 16 bucks for shipping. Yuck. I'll just go ahead and place the order with the store. Thanks for all your help!

[dumbcity]

Having a similar problem after cleaning and adjusting my carbs.

My 350f float bottoms were at an angle when just touching the needle pin. One end of each of the floats was at 22mm, and the other end was at 26mm. I wasn't sure which side of the float to measure to 21mm, so I adjusted the tang. Once I bent it down a bit, my floats became parallel to the carb body when just touching the pin, and measuring at 22mm. I figured 'perfect, all is as it should be'. But now they are completely flooding. So should they have been left at an angle and measured from their lowest point?

I noticed before I put them back together that with the tangs adjusted this way, the pin sat really low in its seat, and took just a little pressure to nudge back up to where it should be. I was hoping the gas flooding in would give it this push, but either it is not, or the floats are set too high.

If anyone has any experience with this I'd appreciate it. My carbs never leaked before this readjustment.

[Colonel]

working the same problem here... Check out the http://forums.sohc4.net/index.php?topic=50697.msg559201#msg559201 thread...

[dumbcity]

Well... I readjusted the tangs back down so that again my floats are at an angle when just making contact with the valve pin. so the sides closest to the pin are at 21-22mm, and the sides further from the pin are 2mm further out.

I realized once I had it apart that it had to be a stuck float, since the change in float height wouldn't be enough to keep the pins from closing before the fuel level hit the drain. Also, my drains aren't cracked and my floats aren't sinking.

It leaked again from one of the carbs when i connected it to the gas and held them level and free from the bike. I let them drain a little, then gave them a good shake and it stopped overflowing.

I'm hoping that as long as I never let the float bowls empty the float arm will never drop low enough to let the needle fall out to the point where it gets stuck.

I know a lot of that was obvious, and nobody is chiming in on this thread anyway, but I hate when I am looking for info and I come across a dead end thread. So I thought I'd answer my own question.

[Johnie]

The way the Honda manual says to check the float level is with the carbs off and on their side.  Then you tip the carb to where the tang just touches the needle valve and then measure.  The measurement is taken from the bottom of the carb body (where the bowl gasket is) to the bottom of the float.  Adjust the tang accordingly.  This is a hard thing to check with the carbs on the bike.