We live in Freeport Maine...

[joe_db]

Is GEM555 still out there?
I hope he gets his boat going. I totally get the issue, if you are new to boating you might think it is like having a car and a mechanic is ready to fix it right then and there and it will be good for the next 100,000 miles.
We once had a magneto go out on an airplane and we got it fixed the next morning for a couple hours labor and parts and were on our way. My wife thought the $120 labor charge was high and told her if it was a boat it would cost twice as much AND we would be stuck here for a week or two waiting for someone to have time to look at it.
(also if it was a boat we wouldn't have the OTHER ignition system to switch to and would have been stuck right where the first one quit)

[GEM555]

Latest update

So I now have an an A4 that will start but will only run on 3 cylinders. One of the valves is sticking. Can I continue to run it this way?

[joe_db]

It has been done, but let us try unsticking it.
There are a few easy tricks to try. My first idea was always to run the engine and slowly pour MMO in the carb.

[CajunSpike]

Upon reviving my A4, it too had a stuck valve. Treatment with MMO directly into the cylinder and the vibration of the engine running, freed it up.

[GEM555]

Have MMO in the gas already. Can smell burning oil in thrvexcust.

[GEM555]

[QUOTE=GEM555;113542]Have MMO in the gas already. Can smell burning oil in the exhaust. The engine is still rapping on 3 cylinders. At least it runs. Can I use it on 3 cylinders?

[sdemore]

When I had two that were badly stuck and MMO wouldn't get to them, I opened the valve side cover and sprayed Sea Foam (spray version) on the stems and into the guides. 15 seconds later, everything was free and working. Now I keep MMO in both the fuel and oil to keep it all clean.

[ndutton]

Have MMO in the gas already. Can smell burning oil in the exhaust.

The guys are talking about a direct infusion of MMO in the offending cylinder rather than a 1% concentration in the fuel.

[TomG]

Have MMO in the gas already. Can smell burning oil in the exhaust. The engine is still rapping on 3 cylinders. At least it runs. Can I use it on 3 cylinders?

Can you? I suppose you could, but why would you if you could unstick the valve easily?

The advice to treat to the gas (and each cylinder) with MMO is great advice.

You state that the engine is running on three cylinders with a sticky valve in the offending cylinder. I'm going to make an assumption that you know which cylinder is not firing and I'm going to assume you know it's a stuck valve due to zero compression and not because of no spark (from a bad plug or wiring.) If you know the cylinder, I would recommend the "Allen wrench" technique to seat the stuck the valve.

1. Remove the spark plug from the offending cylinder.

2. Take an Allen wrench (one of those "L-shaped" steel hex wrenches that you get with your IKEA furniture) and angle in the cylinder hole. Use a long allen wrench (or don't drop a short one into the cylinder!)

3. Find the top of the valve with the bottom side of the allen wrench (this is a little like Luke Skywalker "using the force" because you can't see the valves as they are off to the side of the cylnder towards the carb under the head. It's a bit of a "moment of zen" meets Ty Webb from Caddyshack as you visualize in your head where the valves are).[youtube]0FT_nJ69axs[/youtube]

4. Press down on the valve. Be the valve.

Sometimes this is enough to get the valve to properly seat.

[joe_db]

The guys are talking about a direct infusion of MMO in the offending cylinder rather than a 1% concentration in the fuel.

Yes exactly! Putting it in the gas is a preventative, but unlikely to cure an already stuck valve.

[GEM555]

Follow-up...

Ok, I haven't posted in a while but I thought I'd get back to everyone with the "story so far".

I took a lash at the engine in June, after getting a manual and quickly realized I was unable to make any real progress. I did finally find a mechanic who is familiar with the engine. We spent the summer repeatedly removing the head (sticky valves - we tried Sea Foam to free up the valves. No Joy). Replaced the exhaust manifold, a few of the valves (with new and used plus guides) and put an electronic ignition in. After all of that, with (many) hundreds spent, about the only thing I can rely on is when I get to the boat Friday night the engine will be dead.

For example, I pre-scheduled the mechanic the Friday before Labor Day - when I got there Thursday night, yep! The engine would not start. 1.5 hours later, I had the boat to use over the weekend (only the forth time the entire summer). Each time I use the engine I close the raw water before I shut it down and FOG the engine. MMO in the gas. But once again, last Friday, Sept 7th - dead. No start. No way, no how, no sir. We have no idea WHAT the problem is now - bad gas? (this would be the same tank I've used all summer - we have a spin on water-fuel separator and I've replaced it just on the chance). Who knows?

So that's my A4 experience this season. Got maybe 1 hour of use out of the engine since June 1st. Sailed the boat 4 times.

Guys there HAS to be a better answer than this. Understand now why there isn't a marina within 35 miles north or south of me that will touch the thing. Does anyone want this boat?

[JOHN COOKSON]

Settle Down

Let's get back to basics. What does the engine need to start and run?
Fuel and spark delivered to the cylinders and compression. A properly functioning choke and correctly adjusted timing.

Fuel: Do the cylinders smell of unburned fuel after a period of no start cranking?
Is fuel collecting in the throat of the carburetor after a period of no start cranking? Is the fuel clean (no water in it)?
Spark: Hold a screw driver in a spark plug boot and see if you can jump an arc to a spark plug while cranking. Are the wires on the spark plugs in the correct firing order?
Compression: Do a compression test.
Choke: Is the choke closing all the way?
Timing:Is the rotor pointing to number 1 wire position on the distributor when #1 is at TDC compression.
Let us know which system is not working so we can get it fixed.

TRUE GRIT

[joe_db]

It is possible that engine just needs replacing.
It is also possible it is a $5 repair you all have not found yet.
You would have been well served to live-blog your repair efforts on this thread. The collective knowledge base here far exceeds almost any other engine you could name.
Let us start from the very basic premise that the engine needs to have compression and not have water in the cylinders for it to have a chance of functioning.
Did you pressure test the block? Results?
Did you pressure test the manifold? Results?
Why did you buy a new manifold? What was wrong with the last one?
Did you do a compression test? Results?

[joe_db]

Am I correct in thinking you take the cylinder head off and work on the valves every time you go out?

[GEM555]

Let's get back to basics. What does the engine need to start and run?

Fuel and spark delivered to the cylinders and compression. A properly functioning choke and correctly adjusted timing.
>>>Engine ran fine 5 short days previously. Typically will not start after sitting idle for more than one/two days.

Fuel: Do the cylinders smell of unburned fuel after a period of no start cranking?
>>>How to check? I have to rely on a mechanic for that.

Is fuel collecting in the throat of the carburetor after a period of no start cranking? Is the fuel clean (no water in it)?
>>>How to check? I have to rely on a mechanic for that.

Spark: Hold a screw driver in a spark plug boot and see if you can jump an arc to a spark plug while cranking. Are the wires on the spark plugs in the correct firing order?
>>>Yes. I know that stuff is correct, because the engine ran fine 5 days ago.

Compression: Do a compression test.
>>>I have to rely on a mechanic for that.

Choke: Is the choke closing all the way?
>>>Yes.

Timing:Is the rotor pointing to number 1 wire position on the distributor when #1 is at TDC compression.
>>>I have to rely on a mechanic for that. Just out of curiosity, how in God's name can you see into the engine to determine where anything "is" at any given point in the combustion cycle?

Let us know which system is not working so we can get it fixed.

TRUE GRIT

See my answers above. Thanks!