Engine won't start, 3 cylinders no compression

[JOHN COOKSON]

I squirted in some MMO to those cylinders above the valves.
Progress! Is there hope of those "unsticking" without removing the head?
BW

Yes, you may get the valves unstuck without removing the head. Keep at it. Do you have enough coolant flowing through the engine to run it for awhile even on only1 or2 cylinders? I'll send some good karma your way.
You for sure have some exhaust system\plumbing work to do. I don't understand the details that you have posted R\E the exhaust system and how the water is getting into he engine but I can tell you are on it.
You're hot on the trail. BTW these engines are tough little beasties.

TRUE GRIT

[ndutton]

That is a water jacketed exhaust elbow and depending on the configuration of the internal passages it's possible there was some residual water left inside after you removed the water hose resulting in a wet burp. It's also possible it's breached internally creating your entire problem.

Please have a look at this thread from three years ago:

https://www.moyermarine.com/forums/showthread.php?t=8443

It discusses a similar setup with similar problems and includes a cross sectional picture of a mixing elbow.

[Brent W]

Well I talked with Ken today (very helpful) and I'm getting parts to clean up valves and replace valve springs and also redo exhaust while I'm at it.

Is it necessary to have head machined flat? Obviously I'm going to inspect it first to look for problems.

[tenders]

Have you tried inspecting the valves through the spark plug holes, and trying to gently tap them down through the holes with an Allen wrench or other angled implement? A couple of squirts of MMO on the valves can't hurt.

Once you can work the valves up and down a few times it is not unusual for them to just keep working. Adding a few ounces of MMO to the fuel on a regular basis keeps them that way on my A4.

[Brent W]

Have you tried inspecting the valves through the spark plug holes, and trying to gently tap them down through the holes with an Allen wrench or other angled implement? A couple of squirts of MMO on the valves can't hurt.

Thanks for the reply. Yes I did that. no luck

Long day today! Pulled off manifold, head, and exhaust. I found a collapsed interior on the 16" exhaust hose leading down to the WLM, and it was almost worn thru.

The valves and springs were nasty. lifters and valves stuck, sticky rusty looking goo holding them in place. I will post pictures soon...

I am having a blast pulling it apart, cleaning and fixing stuff as I go. I think this could get addicting.

[tenders]

That's some serious progress, congratulations.

[JOHN COOKSON]

I am having a blast pulling it apart, cleaning and fixing stuff as I go. I think this could get addicting.

Could get?
I'm just afraid you are already addicted.
Welcome to the club.

TRUE GRIT

[Brent W]

Progress

So I took valves, nuts, bolts, head, valve cover, manifold and cleaned them up with brass wire brush in my dremel

I had to cut the pipe at the exhaust flange, then I beat the remaining pipe out of the flange.

Cleaned up the corroded and gross lifters, block surfaces, piston top, etc.

Rebuilt Carb (again) with all new parts. Installed the MMI oil change kit. Painted head and manifold.

Only about 8" clearance on side of motor. Now I know why Don says "I cannot recommend doing this with engine in place" The #4 exhaust valve spring keeper took me 1-1/2 hours to finally install!

Exhaust was another issue. What a royal pain in the butt. I re-did it 3 times before I got something that works, and I'm still not 100% happy. Very little clearance, not the best connection to water lift muffler, hard to access.

But after a 14 hour day yesterday putting everything together...

STARTED UP FIRST TRY! SWEET VICTORY

More to follow...

BW

[JOHN COOKSON]

But after a 14 hour day yesterday putting everything together...
STARTED UP FIRST TRY! SWEET VICTORY
BW

CONGRATULATIONS!
You can work on my A4 anytime.
Hope you stick around the forum. You're a valuable asset to have on board.

TRUE GRIT

[JOHN COOKSON]

Another thought.
If you are going to be "redoing" the exhaust this would be an excellent time to switch to the Thatch Modification where water is introduced into the manifold at the low-end and exits at the high end. The result will be no air pockets in the manifold and improved cooling.
Search the forum by Thatch modification. There are a lot of posts on the subject.

TRUE GRIT

[Brent W]

Another thought.
If you are going to be "redoing" the exhaust this would be an excellent time to switch to the Thatch Modification...

funny you should mention that... read about it last night, and its on my list. Too late now, as I need to run it over to the sling in the morning to have it hauled out.

Went down today and wrapped the exhaust and put some heat shielding on some hoses. The PO had a big spaghetti mess of hose, wires, and duct work in the bilge. Pain in the butt.

I can't get the Idle down past about 1200. At about 1000 it starts bogging down and dies. She runs great at 1400. any help? It should be about 800, correct?

[JOHN COOKSON]

R\E the idle. Some possibilities.
Crud in the idle circuit of the carb or idle set incorrectly. Did you lightly seat the idle needle then back it out 1 1/2 turns?
An air leak.
The advance stuck in the advance position.
Is there a PCV on the engine?

I have my idle down to 600 RPM. It took a bit of effort to do it.

TRUE GRIT

[capnward]

Brent,
Has this idle problem been happening since the carb was cleaned and rebuilt? If so, I suspect your idle screw is backed out to far, making it too lean. Although the manual says back it out 1 and 1/2 turns, Don Moyer told me once that 1 turn is enough. If this is a more recent problem, I think some crud has gotten into your idle jet. I had an idle problem like that, where it struggled below 1400 rpm. It turned out to be a blockage in the idle jet. I couldn't see it until I removed the jet and held it up to the light. File down a small screw driver to fit the jet without scraping the threads in the carb. Once the blockage was removed with a thin wire, and carb reattached, all was well. Run a wire through the idle ports in the throat of the carb while you're at it. Use a new gasket when reassembling the carb to avoid air leaks.
Your work on your engine is an inspiration to us all. Please keep us informed on your progress.