CB77: Leaking fuel issue with carbs

[3030vision]

I handed my CB77 over to a reputable mechanic for what I thought would be more-or-less a tank cleaning and electronic ignition conversion. Evidently he's been struggling with the carbs for a while:

"I fought forever on those carb gaskets and am still getting a dribble from one float bowl mating surface as well as a dribble from the overflow (normally bad float valve or hanging up float from dragging on the gasket). The problem is that the gaskets are about .5mm to small all around. I cleaned all the surfaces and glued them to the carb bodies with a product very similar to what honda uses on a lot of their carbs but that only helped a bit."

And before this:

"looks like I've found the leaking fuel issue. Turns out the carb gaskets you got are made slightly wrong and are causing the floats to hang up and lets the float bowls fill up. I am going to glue the gaskets tonight with some special glue if I can get it from Lowes (we have some at work but closed until 9am). Once I affix the gaskets I can trim the small portion that drags on the floats. Hopefully then I can run it long enough to set the timing and carbs."

Does this problem sound familiar? If so, any suggestions so we can get this sorted out ASAP? I ordered gaskets for the old-style carbs from RetroBikes in Washington state. Not having my bike up and running is killing me.

Thanks in advance for your help.

[joeweir1]

What type of glue are you using?I need to glue my gasket back in place.Thanks

[kustommusic]

Should knock on wood I guess! I reuse old gaskets all the time and haven't suffered a leak yet. Makes me wonder if the mechanic has overtightened the base bolts and warped the carb. body? I hope I'm not muddying the waters here but Iv'e just NEVER had to be that carefull to get gaskets to seal. But hey, Good Luck anyway, Steve

[LOUD MOUSE]

After the gaskets have had gas on them they SWELL and the CORNERS push the EDGES at all sides IN Toward the FLoats. Usually putting the gaskets in the sun will allow they to dry and go back to correct size. Also I now Bend the Floats tword the middle just a bit. .....lm

I handed my CB77 over to a reputable mechanic for what I thought would be more-or-less a tank cleaning and electronic ignition conversion. Evidently he's been struggling with the carbs for a while:

"I fought forever on those carb gaskets and am still getting a dribble from one float bowl mating surface as well as a dribble from the overflow (normally bad float valve or hanging up float from dragging on the gasket). The problem is that the gaskets are about .5mm to small all around. I cleaned all the surfaces and glued them to the carb bodies with a product very similar to what honda uses on a lot of their carbs but that only helped a bit."

And before this:

"looks like I've found the leaking fuel issue. Turns out the carb gaskets you got are made slightly wrong and are causing the floats to hang up and lets the float bowls fill up. I am going to glue the gaskets tonight with some special glue if I can get it from Lowes (we have some at work but closed until 9am). Once I affix the gaskets I can trim the small portion that drags on the floats. Hopefully then I can run it long enough to set the timing and carbs."

Does this problem sound familiar? If so, any suggestions so we can get this sorted out ASAP? I ordered gaskets for the old-style carbs from RetroBikes in Washington state. Not having my bike up and running is killing me.

Thanks in advance for your help.

[3030vision]

After the gaskets have had gas on them they SWELL and the CORNERS push the EDGES at all sides IN Toward the FLoats. Usually putting the gaskets in the sun will allow they to dry and go back to correct size. Also I now Bend the Floats tword the middle just a bit. .....lm

Thanks for your suggestions and insight!

[jesmed]

Probably you've already got it figured out, but I would check the float valves too. Any bit of crud stuck in there will prevent the valve from sealing properly and allow gas to continue leaking into the bowl. If the float height is set correctly and the float is not hanging up and doesn't have a pinhole (have you boiled it to check for leaks?) then the float valve is a likely culprit.