Timing Problem?

[Stormy]

Our A4 has been running really well. We went to start it recently and it turns over, but won't start. We have gas in the carb (took out the in-line water filter as well), spark on each plug (took them out ands visually checked each), but all but #1 cylinder is dry. We tried starting vapor as well to no start. We figured we had a timing problem.

We connected a timing light but found that the light would flash once and no more. Same thing with another light. We pulled plug #1 to check the spark and would get one spark and that's all. I believe we have fixed that problem now. I'll definitely check it to make sure when we get back to the boat and before we start again. But we still have the problem of no engine start.

We haven't had this problem before and haven't had to dive this deep into a timing problem. To date we've addressed any problem by re-tuning, setting points, and/or advancing or retarding by turning the distributor. I haven't really heard of anyone tearing into the engine to fix the timing. Anyone else have this problem? Thanks fopr any input you can provide.
Stormy

[Don Moyer]

Stormy,

There is a good chance that the primary circuit to your coil is breaking down somewhere within the boat's wiring.

You can install a jumper wire between the big battery cable on your starter solenoid and the positive terminal of the coil (this is exactly the same thing as turning the ignition switch ON, so you can't leave the wire installed permanently).

If the engine runs OK with this jumper installed, it would confirm a bad connection somewhere in the boat's electrical system.

You can actually continue using the boat using the jumper wire until you have a chance to correct the problem with your boat's wiring. You'll have to start the engine as normal after connecting the wire, and you'll have to remove the wire to shut off the engine.

[Stormy]

Thanks for the reply Don. We got back to the boat yesterday and verified that the primary was working (we replaced the condenser), and we're now getting consistent spark. We played with the timing but still did not get it to start. We're going to roll the engine out as soon as we can and take a closer look (It'll also give us the opportunity to look at the valves). The timing seems to be off because of the relationship between what we're seeing with the distributor and piston/valves, and what the flywheel is showing. I'll let you know what we find and how this gets resolved. Thanks again for your help. I was happy to find this forum supporting the A4. It's a great engine and more common than some think.
Stormy

[Don Moyer]

Stormy,

Before going to the trouble of rolling your engine out of the engine room, I would check one more time to be sure you have the ignition timing set at top dead center (TDC) of the number one cylinder (at the flywheel end of the engine). It's very easy to overshoot and end up at the bottom of the stroke instead of at the top (having done this myself on quite a few occasions).

The TDC position of the No. 1 cylinder is most easily found by holding a finger over the spark plug hole in the first cylinder, while manually turning the flywheel counterclockwise. As soon as compression is felt, stop turning and look at the position of the roll pin in front of the crankshaft. Continue turning until the roll pin is perfectly vertical. The piston will then be at TDC.

It's very easy to overshoot the TDC position while trying to be certain of a positive indication of compression. In this case, the engine will be rotated a full 1/2 revolution before the roll pin lines up vertically again, and the piston will be at the bottom-most point in its travel (instead of TDC).

Regards,

Don

[Stormy]

Well, we don't have a timing problem as I thought we may have. We went back and checked the engine and found that things were lined up as they should be (thanks for your persistence). I was confusing what I thought was a timing mark with the pin through the shaft. We are also getting a good spark. So, we had good spark but dry cylinders (other than #1). We had relied on 'feel' for compression, but when we checked it we found that compression was low on all cylinders, #1 being the best at about 75-80 (working from memory here!)We went ahead and pulled the engine out (very easy to do) and have had the valves (and seats) ground, but it didn't help the compression much, so... looks like we'll be looking at the rings next. I'm glad this is an easy engine to work on. I'll keep you informed of our progress. Sorry there's so much time between posts, but spare time is somewhat precious right now so we work on it as we can.