A4 stalling out

[Matt]

Hi,
I launched my 1978 Catalina 27 with the A4 yesterday (new boat to me). I reconnected the raw water intake prior to departure and the idled the engine at the dock for a few minutes (spat out water like it's supposed to, etc..).
The engine ran like a champ in forward and reverse on the motor out of the harbor (1/2 mile) turned it off, sailed for 3 hours then started her up again. It was doing well on the way into the harbor going to the slip unitl I really needed it (Murphy's Law).
The engine died sounding (to my untrained ears) as if it ran out of gas (started out with a tank that had 'some' gas in it). I had brought some extra fuel and added about 3 gallons, vented, cranked the engine and it started again but only with a little choke. Now I can idle it but it dies under load.
My question is where should I start? What are some of the most common possibilities?

Thanks,
Matt
Equity C-27
Beverly, MA

[shemandr]

Matt,
You may want to look at the previous thread. Others, including me, have had the stalling problem. Impurities in the gas has been a primary suspect. I rebuilt the carburator, fuel pump, added a Racor fuel filter/seperator and still had problems. Finally, I had the tank cleaned (Off the boat) and relined and the problem seems to be over.
I also probably had an air leak between the manifold and carb. due to my mistake in not using a gasket inadvertantly. An air leak has been suggested for this problem by our esteemed leader, Mr. Moyer.
I've had the boat for 5 years. The first two the engine was perfect. Its only in the last 3 that problems began. Whatever happened with the tank is a relatively recent phenonmenon. I've heard from others that changes in gas additives may be involved.

[Don Moyer]

Matt,

Assuming you're correct about running out of gas, my best guess is that you simply drew a bit of crud into your main jet in the process of refueling and restarting the engine.

The solution would of course be to remove the main jet and clean it. If you're in a time crunch, you probably can get away without disassembling the entire carburetor. However, after cleaning and reinstalling the main jet, I'd leave the main passage plug out until the carburetor is reinstalled on the engine. You can then pump some fuel through the carburetor (and out the bottom into a clean glass jar) to flush out any other crud that might still be in the bottom of the float bowl or in one of the fuel lines, waiting to move into the main jet.

The main passage plug is the 1/2" hex-headed plug in the bottom of the carburetor with the hex-head facing away from the flywheel end of the engine. Be careful to not lose the hard fiber washer under the head of the plug and when reinstalling the plug, do not over-tighten or the washer will extrude out from under the head of the plug.

Regards,

Don Moyer