Gas dripping out of airbox on KZ1100

A perfect petcock does not cure the underlying cause of excessive fuel entering the float bowl for whatever reason.

And such problem may occur while riding the bike when the perfect petcock is flowing fuel.

Good Fortune!

what could be the underlying problems?

greek023 wrote:

what could be the underlying problems?

For example ---

Less than perfect:
- float needle
- float needle seat
- float valve function
- float
- float setting
- float function
- overflow circuit (where applicable)

Danger of excess fuel into float bowl is that the fuel may find its way into the crankcase where it dilutes and contaminates the oil.

If fuel is getting into the airbox, it's likely also getting into the combustion chamber where it flushes down around the pistons and on into the crankcase.

Am thinking most common cause is failure (for whatever reason) of the float needle pointed tip to completely seal itself inside the seat orifice when it's supposed to. Could be from wear, but imo more likely from grit or crud between tip and orifice.

One of the best reasons to run a good in-line fuel filter. Helps keep grit and crud from blocking the seal provided by the float valve (aka needle and seat).

Good Fortune!

Yeah i had the carb bowls apart and the needle's looked like new still.
i'm putting a inline filter in tonight. Also looking around at some other threads on the site i see some guys say tap the carb bowl to seat the valve to the valve seat. Is this a good idea?
Jim

greek023 wrote:

Yeah i had the carb bowls apart and the needle's looked like new still.
i'm putting a inline filter in tonight. Also looking around at some other threads on the site i see some guys say tap the carb bowl to seat the valve to the valve seat. Is this a good idea?
Jim

Not uncommon where fresh dry carbs are installed, and then fuel escapes from overflow.

Rapping smartly against float bowl with plastic hammer sometimes helps the float valve to completely seal, and often without future leakage.

If any fuel whatsoever was allowed into the carbs without first passing through an in-line filter --- Boo on you! :lol:

Good Fortune!

I'll drain the bowls again and try the love tap!

greek023 wrote:

I'll drain the bowls again and try the love tap!

With engine not running, and in-line filter installed, and float bowl drain open, could allow some fuel to run through, which might help flush clear the float valve.

Then close the drain screws.

All before the love tap maneuver.

I usually do the rapping while the engine is running at idle rpm. But it might also be effective when the engine isn't running.

Good Fortune!

Yeah gas is still leaking into the airbox. I'll try a new petcock

smooth move.bj

greek023 wrote:

Yeah gas is still leaking into the airbox. I'll try a new petcock

As per above posts, perfect petcock can't cure faulty function of float or float valve, or clear a clogged overflow circuit.

Merely halting fuel flow at the petcock when the engine isn't running, such as when the bike remains parked, isn't enough.

While riding bike, with perfect petcock flowing perfect fuel, the faulty functioning float and/or float valve, together with clogged overflow circuit, there's a risk that fuel is entering the crankcase, depending on severity of the fault. If Lady Luck keeps smiling, the excess fuel into combustion chamber will be blown out through the exhausts. But watch for fuel-fouled spark plug, and cylinder failing to combust.

Good Fortune!

Thanks Patton. Where is the overflow circuit? I'll check that for a blockage.