Help solve Carb Flooding / Fuel overflow

[trippel]

Well here's the first time I've needed to solve this issue and I'm on my 3rd XS400... The first was sold to afford to move, a hurting decision since that one ran perfect. My second turned out to only be good for parts but it was super cheap and now I have the benefit of spare parts.

This current one, 1982 version, has the issue of overflowing fuel at the carb after the previous owner had it rejetted for no apparent reason other than he thought it should be done. (please take note: If it ain't broke don't fix it!) The overflow begins within a few moments of starting the bike and is rapidly dripping onto the starter - which calls for a quick shutdown.

From what I've gathered lurking on the forum this should primarily be solved using the air mix adjustment screws hidden under tamper caps on the Carb. From looking at several topics across the forum, I felt that this specific issue could benefit from it's own thread.

ASSUME that the internals are clean and correctly assembled, how does one approach this effectively (directly and quickly) so one's wife is less likely to complain upon returning from the garage?

Thanks gang

 

[drewpy]

ASSUME that the internals are clean and correctly assembled, how does one approach this effectively (directly and quickly) so one's wife is less likely to complain upon returning from the garage?

Thanks gang

my carbs were knackered from the PO, lets assume they are really OK?

new one on me

welcome to the forum trippel

 

[OliverB]

May have a float needle valve in one of the carbs sticking and not closing. This could allow fuel to overflow. Can you determine if it is from just one carb? If so, that's the carb you check first.

 

[lhaolpa]

You may have trash on the needle valve or just worn out valve,but jets cause another type of "flooding"and that would be idle related.Actual flooding [overflow]would be float valve.