Topic: CB400F, Gas pouring out of overflow hoses

[Kurt V]

I had previously posted about rebuilding my carbs, but thought perhaps I should figure out the problem with my carbs first.

No previous carb problems. Bike running great. 13K miles on it. A couple of weeks ago I came back from a ride and saw gas just running out of the overflow hoses. I thought maybe a float got stuck open and tried to tap it loose. Seemed to work until I test rode the bike. I could feel the engine bogging from too much gas. When I would turn off the petcock the bogging would stop and the engine would run great. That got me home. Turned the petcock back on and gas was running out of both overflow hoses.

Suggestions as to what to do? Thanks!!

[Steve_K]

My thought is stuck floats or dirt in the float value.  Check your fuel bowl for rust.  If dirty, I would put a container under the carb drain and look for dirt or rust.  Do all the carbs so they are drain clean.  Close them and try again,  and tap the bowls to jaw the floats.   If that doesnot help, you  will need to remove the carbs to inspect.
Steve

[Kurt V]

Steve, thanks for the reply. I will give it a try and hope for the best!

[sir funk]

From your problem description, you  may have just gotten some crap flowing into the carbs that caused it to stick. Make sure your petcock screen is intact and doing its job.

A quick trick you can try is draining the offending carb/carbs and then stick the carb cleaner spray straw up the drain hole and angle it up. Spray as hard as the can will let you, moving it the straw around a bit.  May not permanently fix the issue if your float valves really need to be replaced, but usually takes care of the immediate issue.