Rich:

Let's start with the simple things first.

You need Spark, Fuel, and Compression to make the A-4 go.

Fuel:
Pull the plugs and see if they are damp with unburned fuel. If damp, at least you're getting fuel. You can also check for fuel by removing the flame arrestor from the carburetor and check for the presence of some fuel in intake throat of the carburetor. If you've been cranking the engine for a while you should see some gas there.

Compression:
While you have the plugs out, put your thumb over each of the spark plug holes and crank the engine over a few revolutions. Your thumb should be forced off the hole by compressed air if the valves are working properly. Repeat this test for each cylinder.

Spark:
Pull a wire off of one of the spark plugs and put it close to a ground spot on the engine. Crank the engine over for a little bit. You should get a nice blue/white spark if its OK (be careful not to get zapped!) If no spark we've narrowed it down to electrical problem.

If no spark, let find out if we're getting power to the coil. If you have a voltmeter, check for voltage at the (+) positive terminal with the ignition switch on. There's a problem with the primary circuit, usally the boat's wiring, including possibly the ignition switch. If there is no voltage at the coil, get a piece of wire (at least 14 gauge) and make a jumper which you will attach one end to the output terminal of the alternator(the big terminal that has the big red battery cable attached to it)and attach the other end to the (+) positive terminal on the coil (disconnect all other wires attached to this termial first). Try starting the engine...if it starts, the problem is in the boat somewhere and not the engine.

Good Luck!

Let us know how you make out.

Steve Kaminsky