Intermittent Rough Running/Stalling Frustrations

[MA_Short_Story]

The A4 in my 1969 Pearson Renegade is giving me fits. After a two-year lay-up the motor started shutting down after it was warmed up. The shutdowns USUALLY felt like it was running out of gas (sputtering, misfires, then silence), but occasionally were sudden as if the ignition had been shut off.

I did a complete ignition tune up (points, plugs, wires, rotor, distributor cap, condenser and coil), which made it run much smoother, but didn't solve the shutdown problem. I then put in a new fuel tank, fuel lines (with primer bulb) and fuel filter and cleaned out the main jet on the carb.

Now the engine runs great on the mooring but starts to run rough shortly after setting out and will ultimately die. I've run it under load on the mooring for extended periods with no problems at all but, drop the mooring, head down river and the stumbles and sputters start in.

Any thoughts or suggestions about where to turn next would be greatly appreciated. I've exhausted my trouble shooting ability and patience on this one.

Bill

[Don Moyer]

Bill,

Can you start the engine right back up after it shuts down? If not, you could run the first three steps of our short checklist to determine why it won't start, which would presumably be the same reason it shut down in the first place.

1) Close raw water through hull as soon as it's determined that the engine is not starting within the normal time.

2) FUEL: Remove the flame arrestor and check for the presence of raw fuel. If the choke is closed completely, there should be raw fuel puddled in the bottom of the intake throat within 15 to 20 seconds of cranking (3 or 4 five-second attempts). If the carburetor intake throat is "bone dry" after this amount of cranking, the reason for the non-starting is either a problem in the fuel supply which prevents fuel from getting to the carburetor or some problem within the carburetor that prevents the fuel from getting through the carburetor (most likely a blocked main jet).

3) IGNITION: Remove the secondary lead from the center of the distributor cap and hold it approximately 1/4" from the cylinder head while someone cranks the starter. You should see a good arc between the end of the coil lead and the head that can be stretched to 1/2" or even 3/4". If you see no spark, the reason for non-starting is clearly within the ignition system, most likely a breakdown within the primary ignition circuit.

This quick check of the ignition system does not rule out timing issues. While the Atomic 4 has virtually no history of slipping out of time once the timing has been properly set, if the non-starting follows work that was accomplished on the ignition system, the timing should be rechecked.

Don

[MA_Short_Story]

Don,
Thanks for the reply.
After all my effort, I've determined that it's time to replace the A4. I was finally able to check the compression (thumb in the spark plug hole method) with a friend on board (the starter button is too far from the engine to do both alone) and found #1 & 2 barely pushed my finger off while 3 & 4 blew it away vith vigor. I'll be in touch regarding an exchange v-drive shortly.
Thanks again for all your help, on-line and by phone.
Bill