Carb problems.

I have a 79 KZ750B that I purchased last fall, and I've been tinkering with it all winter. I've got it running pretty good except it suddenly started dumping fuel out the vent tube on the right carb. I've tried everything I can think of. I replaced the float needle and seat, Ive adjusted the floats up and down, I hooked up a clear tube from the drain and adjusted fuel height the way it explains it in mt Kawasaki service manual, but no matter what I do it just keeps leaking. Any Ideas about what could be happening. I did have a repair shop clean the carbs for me, Any help would be highly appreciated. Thanks.

When it starts to overflow try taking a screwdriver handle and banging on the side of the float bowl. If it stops the problem is the float is sticking.

Another possibility is the vacuum petcock has failed and dumping fuel back down the vacuum line and into the carbs. If this is happening it would happen all the time though.

Are you sure you have the hoses hooked up right?

Nessism wrote: When it starts to overflow try taking a screwdriver handle and banging on the side of the float bowl. If it stops the problem is the float is sticking.

Another possibility is the vacuum petcock has failed and dumping fuel back down the vacuum line and into the carbs. If this is happening it would happen all the time though.

The only way you can test the petcock is closing it, removing the fuel line and then put it in "PRI" if fuel comes out even if your diaphram hose is hooked up and your motorcycle is off, maybe it can be a dirty petcock because of a dirty fuel tank. Check that before wasting hundreds of dollars invested in a good carburetor. Sorry for my bad english, I'm from Dominican Republic and it isnt my native language. Hope I helped someone

Nessism wrote: When it starts to overflow try taking a screwdriver handle and banging on the side of the float bowl. If it stops the problem is the float is sticking.

Another possibility is the vacuum petcock has failed and dumping fuel back down the vacuum line and into the carbs. If this is happening it would happen all the time though.

I do have the same exact problem, but it may vary sometimes, sometimes the carb #3 leaks, sometime #1 leaks, sometimes #4 leaks. I dont know what else I can do... Buy needles, floats (if so please send me a link where I can get it, cant find it on ebay or z1enterprises,), I even though of buying a new tank since mine is IRREPARABLE.