Ford 600 Carb

[GaryinKs]

Ford 600 carburetor freezes when its 85 degrees ,tractor acts like its not getting fuel , any ideas? There is ice where the carb meets the intake manifold .

 

[mhb@ufe]

I don't see how that is possible. More likely vapor lock in the fuel line.

 

[used red MN]

Are you seeing this shortly after startup? If so that is not uncommon to see especially on a humid day before the engine builds heat that radiates off the engine and heats everything around the engine up. Have you checked the fuel flow out of the carb drain plug? Needs to be a pint in two minutes starting the catching of the gas 5 seconds after the plug is pulled so the carb bowl drains down.

 

[Sean in PA]

Suction through the carb will cause it to cool. Just like pressure causes heat, negative pressure causes cooling. As used red MN has said, it takes a while before the heat from the running engine gets to the carb via conduction through the intake manifold after you start it. If there is enough restriction to the flow inside the carb, the cooling created by the suction can be enough to cool the body of the carb down to sub-freezing temperatures until it gets warmed up by the engine. If the air is humid, then it will cause water vapor in the air to condense on the body of the carb, which can freeze once it gets cold enough. If the engine continues to run, it will eventually dissipate once it warms up. It sounds like there is too much restriction to the flow inside the carb which is causing too much suction, and possibly there might be water in the fuel as well that is icing up inside the carb, blocking things even more and then causing even more suction.

 

[mhb@ufe]

That's a new one for me. I've never seen that happen on any of my tractors. I know it happens letting air out of tires but didn't think a tractor carb would have enough air flow for that to happen.

 

[Sean in PA]

It happened to me on a 1972 Plymouth Duster with the slant six engine. The exterior icing on the carb that is. It never affected the running of the car, it just melted and evaporated after things warmed up. It had to be within a certain range of temperature and humidity for it to happen. But the mid-atlantic region is known for its high humidity.