Terrible Problem w/ A-4 - Almost Ran Aground - Ideas?

[imagine2frolic]

Think simple first...head gasket. Been there, and done that with the same motor. There be more problems, but maybe a new head gasket will get you some time to save money. Then get a used motor off the internet like craig'slist. I bought one for $1k clean, and in perfect condition.......i2f

[CruiserHopeful]

well today was a good day for fixings, heh.

1) took apart a portion of the exaust and found that the open/shut valve for the exaust is actually a little swinging one-way valve gate. Inside this valve, when upright, a little door swings open when pressure is at one side, and swings shut when there is no pressure. That was frozen open... so it was operating incorrectly. Sprayed a bunch of WD-40 all over it and let it sit. Now it works as it should, and the exaust seems more forceful when shooting out the back
2) Cleared out the gas tank breather hose... there was so much nasty sludge in there it wasnt funny at all. defiantly wasnt allowing air to go through it.
3) Installed new spark plugs that are one level hotter than the originals.
4) Made a ghetto-rigged PCV valve that directs the air coming out of the oil filler cap back into the spark arrestor next to the carb. So now the smoke is simply recirculated directly back into the intake... There is actually a "real" PCV valve for the atomic four that can be bought, but I will try this for now and see what happens



ran good at neutral, revved it up for a bit and it didnt die (that was the biggest problem, and it may be fixed). Still smoking, so at some point will need to fix up the engine - but that can wait until winter haha. This is the time for sailing.

Tomorrow I will take it out and putter around, see what happens, see if it dies.

GOD I hope not.

[svquest2]

Would this be any good for you? Sounds like a super deal.

http://boatdiesel.com/Forums/Thread....hread_ID=29493

[mesquaukee]

You might want to, while you are still tied to the dock, put it in gear and rev it up to half speed.

Best of luck.

[CruiserHopeful]

Originally Posted by mesquaukee

You might want to, while you are still tied to the dock, put it in gear and rev it up to half speed.

Best of luck.

thanks for all your help, I'll be sure to let you guys know what happens

[Ex-Calif]

Good news Cruiser. Let's hope you can nurse it along till the season ends.
Enjoy your sailing.

[imagine2frolic]

Thinking simple is always the way to go first. If you have sludge in the fuel you may belooking forward to cleaning the carb. If she won't throttle up, but will when the choke is out. It's time to clean the carb, or rebuild........i2f

[imagine2frolic]

Another thought....is the pipe coming out of the manifold pointed down? It needs to naturally drain with gravity, and not have a valve in it.......i2f

[Dick Pluta]

1. If you have good compression all must be well with gaskets, rings and valves seats. You won't get pressure otherwise.

2. Whatever is happening is happening outside the cylinders.

3. In an A4 the valves are in the block. There are intake and exhaust passages cast into the block. There could be a crack of some kind between the passages and the oil sump. If the water jacket is involved that could explain the water in the cylinders.

4. The manifold, which is a combined intake and exhaust, bolts to the block. If memory serves, there are no water connections between the manifold and the block so it is unlikely there is a problem with the manifold.

I'd bet on an internal crack in the block. Once the water jacket, the sump and the manifold passages are connected and the valves are open stuff could flow all over the place. An hour of inspection beats a month of speculation. Pull it, disassemble it and look around.

Dick Pluta
AEGEA

[SkiprJohn]

Aloha Cruiser,
I've been watching this thread. Congratulations and I hope you get a couple more seasons out of your A-4. After going out check for plug fouling after a few hours of motoring.
Kind regards,
JohnL