floats in Mkuni carbs

[Ramjam]

Hi team
please tell me if one float is leaking - does this mean that the excess gasoline makes its way into the next carb and floods this one too??
thanks for your help
best
MJ

[tz375]

No. It just means that one carb is too full and will leak.

The only way for excess in one bowl to reach another carbs is if the drain/overflow hoses are linked.

[GT750Battleship]

Hi,I also found if the float is damaged in anyway...dented or the like,you will have flooding problems...this happened with my GT750A,replaced a dented float with a new one,& the problem stopped
Cheers,
Roger

[Ramjam]

so why then is that when number one float is leakng and takng in gas, the number two also overflows. When i examine no 2 float its perfect; i then 'repair' number 1 and everythng is fine. no flooding on either.

[pearljam724]

You need to check and clear the overflow tubes that are inside the bowls. They clog very easily if you have contaminants in your tank. Those contaminants float around at the top of your fuel level inside the bowls. Clogging the overflow tubes. When one clogs, it will flood that same cylinder. Gas can and will move to the next cylinder or carb if your flooding is severe enough. Or you leave you petcock on prime too long. A good indication that all tubes are cleared is leaving the petcock on prime long enough to verify that flooding of gas comes out the hoses attached to the bowls onto the ground as it should. An easy way to clear the overflow tubes without removing the carbs. Is to blow into the drain hoses by mouth. That usually clears the tubes. But, regardless. If your tank is need of being sealed it will reoccur in a very short time period. You have to address both issues immediately. I would properly seal the tank, install an inline fuel filter and remove the carbs a first time to properly clean them. Otherwise, it's a never ending battle. You can prepare a float by soldering it. Unless, it's riddled with cracks. If that's the case, you're better off replacing it. Because, it will continue to crack all over.

[tz375]

If the three carbs on your bike have individual fuel feeds, that should not happen. B U T if they have a single feed to one and are cross connected, the rising fuel in one will potentially push more fuel to the one next to it, but the float valve on #2 should stop that from happening.

Do your carbs have small bore drain/overflow tubes and if so are they connected to each other?

Maybe you can post a picture of them and something may occur to us.

[Ramjam]

they have the tiny over flow pipes at the bottom of each bowel which i connected to indvidual pipes so i could see if they are over flowing and which one of course

[Ramjam]

You need to check and clear the overflow tubes that are inside the bowls. They clog very easily if you have contaminants in your tank. Those contaminants float around at the top of your fuel level inside the bowls. Clogging the overflow tubes. When one clogs, it will flood that same cylinder. Gas can and will move to the next cylinder or carb if your flooding is severe enough. Or you leave you petcock on prime too long. A good indication that all tubes are cleared is leaving the petcock on prime long enough to verify that flooding of gas comes out the hoses attached to the bowls onto the ground as it should. An easy way to clear the overflow tubes without removing the carbs. Is to blow into the drain hoses by mouth. That usually clears the tubes. But, regardless. If your tank is need of being sealed it will reoccur in a very short time period. You have to address both issues immediately. I would properly seal the tank, install an inline fuel filter and remove the carbs a first time to properly clean them. Otherwise, it's a never ending battle. You can prepare a float by soldering it. Unless, it's riddled with cracks. If that's the case, you're better off replacing it. Because, it will continue to crack all over.

absolutely brilliant advice, many thanks Pearl Jam

[tz375]

............. When one clogs, it will flood that same cylinder. Gas can and will move to the next cylinder or carb if your flooding is severe enough. ..................

How does that work? Each carb float valve should shut off teh flow even if it's just seeping in from somewhere, the float on the adjacent carb should rise and shut off any further flow.

What is the mechanism for a cross flooding situation?

[pearljam724]

............. When one clogs, it will flood that same cylinder. Gas can and will move to the next cylinder or carb if your flooding is severe enough. ..................

How does that work? Each carb float valve should shut off teh flow even if it's just seeping in from somewhere, the float on the adjacent carb should rise and shut off any further flow.

What is the mechanism for a cross flooding situation?

Chances are, if the carb bowls are being introduced with floating contaminants to clog an over flow tube. Chances are, the needle valve seat can be blocked by additional contaminants as well. Tanks do get bad enough and some people don't take the initiative to seal and install a filter. It's very possible that a tube or tubes have been clogged for a longer period. The first time the carb gets contamination jammed into the seats or needle valves. The flooding can move to the next carb. When more than one seat or valve is clogged with contaminants causing flooding of one or more cylinders. If each carb body shares the same fuel feed. Or 2 seats or valves are blocked, regardless of them sharing the same fuel feed.