carburetors leaking gas into air cleaners

[Downeaster]

Never Assume. You have "new" in quotes, so I'm guessing they were rebuilt by someone?

Take them apart and verify everything yourself, it's the only way to be sure.

 

[ippytattoo]

If it is a vacuum petcock and you are getting flow at all times check to see if gas is flowing back through the vacuum line.

 

[Drew650]

If it is a vacuum petcock and you are getting flow at all times check to see if gas is flowing back through the vacuum line.

I did check and there was no gas coming from the vacuum line

 

[curraninc]

I had the same issue on 78 xs650 special with duel vacuum petcocks. Swapped over to the replacement non-vacuum petcocks that have on/off lever so gas will stop flowing when bike is turned off. Then overhauled both carburetor with new floats and valves. Be precise when setting the floats so they seat properly to prevent the gas from leaking again. Follow the forums on carb overhauls to help you out.

 

[Drew650]

My carbs were rebuilt professionally and by my mistake assumed they were good to go. Could have been shipping that fumbled with the floats and needle valve. But I fixed it following the carb guide and she fired up. I need to adjust the idle. And replace a gasket spitting out oil but as far as the carbs go I'm pretty optimistic that it's going to work well.

 

[richardthemotorcycle1]

had that happen to me, yeah float needed adjusted.

 

[Drew650]

Hey guys,
so I got a new petcock from mikes as the vacuum one was leaking. Thought this may have fixed the problem after fixing the float valve. But about halfway through my short ride, gas started leaking out of the air filter on the left side again. Does anyone know the proper height or how to adjust the EX500 floats? The drain plug is different on them to do the clear tube method. The needle valves look brand new. Thanks

 

[grizld1]

If the overflow happened right away, it's due to float valves. Doesn't matter if they're new if they're Chinese repops; many of those are bad out of the bag. You'd be well advised in the future to connect the carbs to a fuel source and inspect float level on the bench before installation; 17 mm. is the spec for the EX500 carbies.

 

[Drew650]

If the overflow happened right away, it's due to float valves. Doesn't matter if they're new if they're Chinese repops; many of those are bad out of the bag. You'd be well advised in the future to connect the carbs to a fuel source and inspect float level on the bench before installation; 17 mm. is the spec for the EX500 carbies.

It didn't happen right away. I let it idle and warm up for at least 5 min. No leaks. I stopped at a stop sign and looked down and saw nothing and when I was pulling into my driveway is when I started seeing gas on my pant leg. And when I parked it, I saw it continue to come out at a steady drip. I then cut off the flow at the (manual) petcock.

Thanks on the advice and measurement [emoji106]

 

[grizld1]

The problem isn't petcock or float level (petcock has to be open to run, float level issue would show up right away). Sounds like debris in the float valve; just drop the float bowl and open the petcock to flush. Inline fuel filters are a must-have.

 

[Drew650]

I have an in line fuel filter. But it was a recent add on. I plan on doing the q tip and steel wool trick to clean the seat for the valve. I'll check back when done.