carb over flowing

[milkman]

Evening all
the niggles continue

When on teh side stand, my RIGHT side carb constantly overflows, you can feel all the petrol at the back of the carb, enough it visibly leaves a pubbl unnder the bike

So what is it? Float bowl isn't telling any obvious stories, I tightend teh feul line, though t it might be cracked but its ok.

ANy suggestions most apreciated. Using teh bike as a run around to work and back, if i forget to turn teh fuel tap off I'm losing 50km /tank!

[Bob_Roller]

I don't know if you have performed any maintenance on the carbs, but it sounds like a problem with the float needle valve ( rubber tip degraded), float ( heavy due to absorbing fuel), or float adjustment is not correct, or a combination of all three.

These bikes don't like to be left on the side stand for any real length of time.

Also, are you turning the fuel tap off when parking the bike?

[drewboid]

Unusual that the RIGHT side overflows since the bike leans to the LEFT when on the side stand.  Is there any problem if it is on the main center stand?
If so it sounds like the float needle needs to be replaced - although it may be just a piece of grit caught on the tip.  Also check if the floats are still in good condition - they can deteriorate and cause the carb to overflow. Check the float level to see if it is out of adjustment.
Do you have the independent "alcohol proof" floats - they get out of adjustment easily.
Check snowbums web site for an article on the floats and adjusting them:
http://home.jps.net/~snowbum/bingindependent.htm

Get into the habit of shutting the tap when you stop - if you get a piece of grit caught again you could drain the tank.
Do you have any fuel filters added in the lines? - older tanks can shed rust or pieces of the lining.

[Rob Valdez 79 R65]

These guys covered it, but I will emphasize that it is important to shut off the fuel AT EVERY PARKING SITUATION.

I usually shut mine off several houses away from home, or when I am getting close to turning into the parking lot at work.


The fuel line should be renewed every few years.  I do mine every other.

[Bob_Roller]

There is a filter on the fuel line nut that threads into the bottom of the tank, check to see if it's there.

I've added a clear plastic body, sintered element, fuel filter to my bike, and it has reduced the amount of fine grit and water in the float bowls.

[nhmaf]

+1 to all the above - I'd first check for the needle tip sealing first and/or sticking float as they are the easiest to check/ most likely to occur, and *definitely* do go into the habit of turning off the fuel when you are going to be parking/stopping the bike for more than a few minutes..

[Justin B.]

I have also had the stock rubber fuel lines "crumble and flake" on the insides which allows chunks to get down into the float needle seat and interfere with the needle's ability to close.

[MrRiden]

I've got that on the left side! Workaround= shut off fuel tap when parked on sidestand! Fix= remove clean and inspect fuel bowl inlet, replace seat, float, needle valve. I'll get to it when it's 115deg and too hot to ride in the desert [my version of winter] 'till then don't wear the nice new boots. I heartily agree with the previous posts![smiley=beer.gif]
rich

[westfalian_alien]

Hello Milkman,
I agree the same way as Mr Riden.
Furthermore,

I've added a clear plastic body, sintered element, fuel filter to my bike, and it has reduced the amount of fine grit and water in the float bowls.

Besides that, I strongly recommend the change of the needle valves every 60 000 kms. They'll show a circular "worn-out" image after this time. Be careful then by removing their fittings: they easily can be broken by forcing the (steel-made) needle out of it's (zinc) seat in the wrong direction. In this case, you'll loose the whole carburettor.
Drive safely
+++
westfalian alien

[Ed Miller]

Are you talking about the float needle seats, or the float needles?  I don't know how to change the float needle seats, but I'm not quite to 60,000 miles yet.

OH!  I just noticed you said km, not miles.  Yeah, I'm past that.

[thrang]

Have you checked the cork gaskets, and made sure that there is no crap gunging up the bowl to body groove if thats fine then I'd just replace the floats and needle. But if you're doing that for the amount of time and money involved you might as well as just recondition both of them with a rebulid kit.

Tony

[stevie]

I had this problem with my 81 (flat top carbs). It may sound a bit "heath robinson" but a sharp tap with a rubber mallet to the offending carb cured the problem.

Regards Steve.

[westfalian_alien]

Sorry, Ed,
for my language lackings:

Are you talking about the float needle seats, or the float needles?

I'm referring to the float needles. And sorry for the "km"s. Besides that: 60 000 km's equals 37 282 mls.
Drive safely
+++
westfalien alien

[Ed Miller]

Don't worry about it alien, I was just reading too fast.  I have a pretty good idea of the conversion as I run races: 5, 10, 15, or 50 km, but I feel the pain in miles.  

[Justin B.]

Ed, I had corresponded with Bing some time back about a carb I was having fits with (turned out to be rubber grains from fuel line) and they told me that if the carb was one that used the rubber tipped needles then the seat would virtually last forever.  But, if they are to be replaced you have to make a "remover",.  I think the process is to drill up through the seat, tap the hole, install the "puller gizmo" over the seat, screw in a screw and allow it to pull out the seat.  Hmmm, that probably made no sense, if you are an ammunition reloader then you pull the seat the same way you would use a "stuck case extractor" to remove a case stuck in a sizing die...  It would be much easier to draw than to explain! ;-)