Last week I mentioned that the Healey had a carburetor issue related to a sticking float valve. This would explain the fuel economy that barely broke into double figures on the last tank, not to mention the smell of unburned gasoline that enveloped the car when idling. Just switching the Healey’s ignition on would cause a disturbing stream of gasoline to run out of the overflow on the forward carburetor. Clearly this issue needs to be resolved before I take the Healey out for early Spring hooning.
A carburetor’s fuel supply works a little bit like your toilet. Each of the Healey’s carburetors has a
chamber that fills with fuel, ready to be consumed by the engine. As the engine consumes the fuel in the carburetor, a brass float sinks along with the fuel level. Just like in your toilet tank, as the float sinks a valve opens that allows more liquid into the chamber. The Healey’s overflowing carburetor is similar to a toilet that keeps running on until you jiggle the handle. Instead of making an annoying sound and increasing your water bill, the Healey’s sticking valve creates a very real risk of fiery explodey death.
In the picture above, I’ve circle the problem area. The Healey’s intake and exhaust manifolds are on the same side of the engine. Having a stream of fuel run out of a carburetor on a car like the Healey is more than a little frightening, as the searing hot exhaust is right there.
The tops of the float chambers come off quite easily, simply remove the fuel line and unbolt the top of the float chamber to expose our area of concern. The float has a linkage that works a ball valve to control the flow of fuel into the chamber. These valves can get jammed open by either grit from the fuel tank or by shellac that builds up from old gas. I sprayed carb cleaner into and around the valve to clean it out and get it working properly again.
While I was under the hood, I did the same cleaning to the other carburetor and cleared out the filter screens in both. After putting everything back together, I fired up the car and was happy to see the carbs not spilling fuel out of their overflows. The Healey appears to be more or less ready for action. It has a bit of a misfire while cold, but smooths out nicely as it comes up to operating temperature.
I can’t wait to get some more nice weather to go for some fun Healey rides as Spring approaches.