Bizarre Choke Role Reversal

[Unregistered]

I operate my 79 Ericson 29 in Seattle. Doing an engine run the other day, the choke was acting in reverse where it ran smothly at higher RPMs (after being warmed up) with the choke pulled and gullumphed when fuel was put to it with the choke disengaged (pushed in). I checked the choke positions during each test, and found that the smooth running had the choke arm (controlled by the cable) in the 90 degree aspect and when unable to handle the gas, it is at an 170 degree aspect. There is a spring that pulls the choke to the better running position. What is the correct running position of the choke arm at the engine once it is warmed up?

[JimG]

I had a similar problem and it turned out the carb gasket was leaking - running way lean without the choke on...

[Don Moyer]

I'm not sure that I understand your description of your choke lever positioning. If I were on your boat, I'd remove the flame arrestor housing and check the actual positioning of the choke valve itself as you pull the choke knob in the cockpit all the way to the full extend position, and then push it back in.

When you pull the choke knob all the way to the full out position, the choke valve in the carburetor should be fully closed. When you push the knob all the way in, the choke valve in the intake throat should be fully open (horizontal).

As the choke valve moves from full open to full closed, the bottom of the external arm moves from approximately a 7:00 position to a 4:00 position. If the cable is disconnected, the return spring should pull the choke assembly to the fully open position.

In most cases, when the choke valve does not follow the proper positioning of the cable and choke lever, it is because the retaining nut that secures the external choke lever to the choke shaft has become loose and is allowing the choke valve to assume random positions.

Don

[daveinrenton]

The bizarre choke behavior

Don, As soon as I sent my note to you, several responses popped up relating to similar conditions. One of your advice notes to another user suggested that when the engine only runs smoothly with the choke engaged, it is likely one of the carb jets is clogged. Since it made logical sense that the fuel was being starved, that spurred me to remove the carburator and thoroughly clean it. It was pretty gross! After dissassembling and emptying a can of carb cleaner in every nook, jet, and cranny, I reassembled and reinstalled the unit, pulled the choke lever and it started with a will! After warming for a few moments, the familiar chugging of a rich fuel/air mix began at which time I disengaged the choke and smooth running ensued.

Good advice and a lucky execution by a do-it-yourself-and-know-just-enough-to-be-dangerous mechanic.

Thanks for your service to the A4 community.

Dave Stevens

[Don Moyer]

Dave,

Glad things turned out well for you.

Don