2 of 4 carb. are leaking... And it's not the needle valves!

[Supermark]

Mercury 115hp 1992 4 cyl.
#2 and #4 (from the top) gaz flooding carburators only when I stop the engine. Needles valve are already changed and seat is cleaned. I check the float level, and it's the same for each carburator and it's good. A vent is cloged? I'm sure somebody on that forum can resolve my problem. Thank you. (sorry for my bad english)

 

[CharlieB]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

You may have to take another look at the needles and seats.

Viton tip needles used a brass seat, other kits have a solid METAL needle which uses a rubber seat pressed down into the seat.

 

[Supermark]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

First, thank you to help me. I will check it for a thrid time! But, I have to be more precise; when I stop the engine, carb #2 and #4 begin to flood, but only a few drops (4-8 drops). After that, carb. doesn't leak. That's why I think the problem comes not from the needles :redface: Thank you.

Marc

 

[86RajunCajun]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

Probably leaking from the carb over flow port, meaning the needles arent sealing off the fuel flow and flooding the bowls over.

Replace all the needles and seats...for as cheap as they are, why wouldnt you?

GL
RC

 

[Supermark]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

The needles valve are brand new and I lap a little bit the seat, because there permanent. When I dismantle carb. #2 and #4, the seat let a fine ring mark around the needles valve, so it was sealing, no?

 

[jhamill1986]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

with the carb dismantled try blowing compressed air into the fuel inlet with the float seated. if any air blows through then you have a blockage. or just hook it up to the fuel line and squeeze the primer bulb. this is easier to see if you have a blockage or not.

 

[Supermark]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

Thank you, good idea, I will try and let you know

 

[j_martin]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

with the carb dismantled try blowing compressed air into the fuel inlet with the float seated. if any air blows through then you have a blockage. or just hook it up to the fuel line and squeeze the primer bulb. this is easier to see if you have a blockage or not.

About 8 lbs pressure will overcome a seated needle. Probably much less compressed air for an inverted float-seated needle in your hand.

you might be missing a gasket, or used one that is not seating. Not sure of yer engine, but the WH carbs on the V6's have a little innocuous gasket wrapped around the idle tube that can cause all kinds of grief is it isn't perfect.

 

[Supermark]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

Ok, the fuel pressure test with the primer bulb and nothing is leaking. My carb. are WME 33, but you have to be sure that I will check every gasket and particulary around the idle tube if I have. I'll be back...

 

[rcopenha]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

I have a simalar question pertaining to the flooding issue. I have 1990 200HP V6 model Johnson and two of the carbs are overflowing. The needle valves look fine but do the poly float ever get gass logged and not maintain the proper float level?

 

[Supermark]

Re: 2 of 4 carb. are leaking... And it's not the needle valves!

I have a simalar question pertaining to the flooding issue. I have 1990 200HP V6 model Johnson and two of the carbs are overflowing. The needle valves look fine but do the poly float ever get gass logged and not maintain the proper float level?

With old brass float that think happen frequently, but with poly float, as I know, its rare and have 2 on the same engine; better take lotery bill!