using a testing light to check timing not working as described in video.

[capnward]

My A4 ran perfectly all last summer, probably over 100 hours running, but I haven't started it since October. Now it won't start. I kept the heat on in the boat, so no freezing. I have changed fuel filters, lubricated the flyweights, cleaned carb and jets, put on new cap and rotor, but no sign of firing. The choke works properly, closing completely. The idle mixture screw is turned out from the seat 1 turn, The adjustable main jet is turned out 1.5 turns.
I know fuel is in the carb; I have pumped the bail on the mech fuel pump until it went loose, and the fuel pressure gauge went up to about 3. There is good spark from the top of the coil lead to the block.
So, to make sure the timing is right, I watched Don Moyer's video showing how to set timing. The roll pin is covered by a pulley for the Raw water pump, so I have to feel for the position of the cylinder with a wire. First, I turned the engine to #1 TDC, with the #1 cylinder is at the top of the compression stroke, and the rotor pointing to starboard away from the engine. Then with the ignition switch on, I attached a testing light across the coil terminals and turned the distributor base as in the video, but could not get it to light up, except occasionally and then only for a second. When I move the (new) testing light to connect the positive terminal of the coil to the block it lights steadily. I would suspect the coil, but it creates a good spark when the wire from its center is held above the block. I think I just can't get a good enough connection with the pointy end of the tester on the negative coil terminal.
Connecting the point of the tester to the negative terminal with a wire with a clamp on both ends didn't work either.
So now I will try putting cap and plug wires back on and see if it will fire with the distributor turned to various positions.

[Surcouf]

So these are the 4 Masters of Firing:
- gas: to be 100% sure your engine is just not craving for something combustible, just try with "easy start / start pilot", or any other spray you like to use for that. If it fires with that... you know you have a fuel issue. Easy test to do
- air: compression: have you checked cylinders compression? unlikely, but you could have a couple valves blocked... easy check with compression tool
- air discharge: any chance you could have a collapsed flexible discharge hose (I had one on my C27)? a closed exhaust valve (rare but seen in the past)?.
- spark, and spark at the right time. Seems that you have covered those ones, but if you have verified the first 3 items (gas/compression/exhaust), it is likely the culprit.

Good luck

[SbMolly]

“except occasionally and then only for a second”

That is what it’s supposed to do. When the ignition is on, there should be constant positive power to the + terminal on the coil. The negative terminal should pulse, as the distributor turns. Whether you have points, or electronic ignition, when it hits the rotation point where negative it pulsed to the coil - the coil releases a spark.

Sounds like you are getting a spark out of the main coil wire, which feeds the distributor? If so, I suggest that before you start worrying about the timing being wrong - confirm you are getting a spark out of the distributor, to each cylinder. Few ways to do this. my favorite is with a spark tester ( avsilable at most auto parts stores for under ten bucks) or you can just hold a plug wire close to the block when cranking, and look for a spark. Or you can put a timing light on the plug wire, and crank the motor, looking for the light to flash. But i once had a weak spark that had enough juice to fire the timing light, but not enough to create a spark - so don’t consider this a reliable test.

A lot of things can go wrong when an engine sits for months - but the ignition timing changing itself should not be one of them - so my guess is that you are chasing the wrong problem. Take the cap off, and crank the engine. Does the rotor spin? You replaced the cap and rotor, are you certain you got the firing order correct, and had 1 on the correct position on the cap?

[Sam]

You just received good info about testing for spark to the plugs vs just spark to block from coil wire. My question is do you have " points" or upgraded to electronic ignition? Not sure how good some of your past test connections were but if you have points a pesky problem of almost invisible corrosion on the points can occur from sitting all winter eliminating contact and thusly plugs not fireing. Problem solved with just a swipe or two of emory cloth or point file [if you can find one]. If you have electronic ignition I would look closely to the cap and the rotor.

[capnward]

Thanks for the help.
I have electronic ignition. Cap and rotor are brand new. Rotor turns with engine. #1 plug wire goes to correct place on the cap, to line up with the rotor pointing directly away from the engine at #1 TDC.
Firing order is 1-2-4-3.
In the Moyer video he was able to get the testing light to light steadily by turning the distributor until it lit, then he would turn it counterclockwise until it turned off, and that was the position to secure the distributor for initial static timing. I was unable to do that, apparently because I couldn't get a good enough connection of the light to the negative terminal. It would not light steadily, so I couldn't see where the distributor should be secured. I understand that when the engine is turning the pulse to each spark plug is momentary.
I put the distributor in the approximate setting to duplicate where it was when it ran. There was still no firing in the cylinders.
One thing I did not mention is I put a large strawful of MMO into each cylinder and let it soak for some days before trying to start. After cranking I noticed MMO at the bottom of the carb, under the choke. The plugs are oily. This may be preventing ignition in the combustion chamber.
After checking the compression, I will check for spark at the end of each plug wire. I will also clean oil off the plugs.

[Sam]

I apologize for my simplistic answer to an experienced afourian. I got you mixed up with another poster who is new and needs more basic help.

Relative to your theory on the MMO/wet plugs every fall at layup I skirt a couple of tablespoons of oil into each cylinder after oil change. In the spring I start the A4 with a set of older but cleaned and gapped plugs, a little choke AND starting fluid. It stumbles a little bit then runs smoothly. I then change to my newer plugs. This is on a 1966 never rebuilt early engine [owned for 45 yrs] In earlier years without the starting fluid it would eventually start but took a little more effort and thought.

[SbMolly]

One thing that really surprised me with this motor, and I was just out messing with mine a few minutes ago, is how little impact turning the distributor to advance or retard timing a few degrees has on the idling. In other worlds, even if you are close, it should start and run. And if you are wayyy off, should still hear some combustion - with flames popping out the carb or exhaust.

Is your test light an LED, or regular bulb? I can’t remember which, but there are some tests you can’t do with LED ( because it flickers with such low voltage) and some that won’t work with incandescent - because you don’t get enough voltage.

My guess is still that you aren’t getting spark in the cylinders, not that you are getting a spark at the wrong time.

[capnward]

Today I checked compression. Results are: #1, 110. #2, 130. #3, 75. #4, 135.
The 75 reading is concerning, but it should not keep it from starting, and may solve itself as it warms up. Then I proceeded to test the spark at each sparkplug wire, by connecting the plug to the wire and laying it flat on the block, holding it down on the block with a wooden stick. The #4 plug had a faint spark at first, then no spark. Then the three other plugs would not spark either. Power is good from the ignition switch to the positive coil terminal. Then I tested the secondary current from the center of the coil to the block, which worked before. No spark this time, so I think I have a bad connection inside the rubber boot which connects to the center of the coil. The wire pulled out from the clamp inside the boot the other day, and I may not have hooked it up right. Tomorrow I will seek help making that connection correctly. I will also test the ohms in the coil. I may need a new coil, although it worked great all last year. I will order one from Moyer, in case. It sure would be nice if I could make the test light glow when connected across the coil terminals, by rotating the distributor, as shown in the video.
Another possibility is I may have shorted out the ammeter. I took the battery out to fill the cells with water, and when reattaching it, I left the power switch on and accidentally dropped the big hot positive connector onto the ammeter. Big sparks flew for a second, and I was lucky to not get a shock. I wonder how to test the ammeter to make sure it is ok. Maybe this is why the coil seems to have stopped working.

[edwardc]

Those multimeters usually have a fuse in the ammeter circuit. If its replaceable, you'll have to open the case to do it.

There's no danger of shock with 12 volts, but you could get a nasty burn, as batteries can dump hundreds of amps in a split second when shorted, heating wires, tools, jewelry to red-hot incandescence.

[Dave Neptune]

To Edwards point, a friend of mine with a big power boat was showing off his new "batteries" a pack of 4D's, I think it was 12 maybe more. As he was showing them his "Rolex" brushed a positive lug and the box frame at the same time just for an instant. The watch literally melted and fused itself all the way around his wrist. It was very serious localized burn and he was lucky to still have the use of his hand. At the hospital they had to cut off the ruined watch. We were at Catalina and needed to get another friend to take him back to the mainland then to the hospital. It was very ugly!!!

Be very careful no matter the voltage when you have a large amount of amps.

Dave Neptune

[capnward]

problem solved, engine runs

Just to let y'all know the old A4 fired right up today. All is well! Bought some starting fluid but didn't use or need it.
It was a bad connection inside the rubber boot at the center of the coil. Found someone with the right crimping tool. Put in new plugs. Engine hammered (tapped? knocked?) loudly at first, like I imagine a stuck valve would, but as it warmed up it smoothed out. I am guessing that was the valve at the cylinder with the low compression freeing up. Ran for an hour. At 1500 RPM under load the vacuum gauge was at 10, as usual. No damage to coil, alternator or EI, despite the big 'ZAP'. Next winter I will keep running it periodically.
Am so grateful for this forum, and especially for the people at Moyer Marine. You guys rock!