Engine not starting

[Kemp]

Early model A4 running last year, went to start this weekend for the first time since last November (long time) and engine will not fire. Just put in electronic fuel pump but didn't replace the points yet. I have good fuel flow to the carb and removing front and rear plugs got good fire with test plug, and the plugs were wet with fuel after trying to start. I even used ether and didn't get it to fire off that. Looked in distributor and it's a rusty interior in there. I bought your electronic ignition replacement for the Prestolite but didn't want to replace too many system parts until it fired up (electronic fuel pump, then electronic ignition). Two things come to mind, replace points and condensor with conventional parts or the electonic fuel pump power attached to the coil is too much for the coil and ignition. I will do a compression test too if that is another option. What do I replace to troubleshoot and get her back?
Thanks Kemp Dawson

[Don Moyer]

Kemp,

Here is a list of items we prepared recently to check when an engine will not start:

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 (which is normal for updraft carburetors), there should be raw fuel puddled in the bottom of the intake throat within 15 to 20 seconds of cranking. 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 (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 layer of corrosion on the contact surfaces of the points or 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.

4) COMPRESSION: With all spark plugs removed, hold your thumb over each spark plug hole to check compression as someone cranks the engine for a second or two on each cylinder with the starter. An Atomic 4 will usually start if any two cylinders have normal compression as indicated below.

a. Compression sufficient to force past your thumb no matter how hard you press it against the plug hole would confirm normal compression of approximately 85 psi or above.

b. If you can hold your thumb against the compression, but not easily, a compression value of approximately 40 to 50 psi would be indicated, and starting could be problematic.

c. If you feel virtually no compression on any one of the cylinders, the problem is likely a stuck valve.

5) If all of the above checks prove to be satisfactory and the engine still won't start, the problem is probably somewhere within the secondary ignition system, downstream of the coil. The components within this part of the secondary ignition system are very difficult to inspect, but they are fortunately not very expensive, so I recommend replacing them in the following sequence: plugs, distributor cap, plug wires and rotor.

Regards,

Don

[Kemp Dawson]

Don,
Thanks for the advice. I will go down the list and get this running so we can finally go out. We have a Sea Scout group to take out all next week and this is one of the six boats in the group.

Kemp Dawson