No idea what to do next

[CaptainCronos]

The boat is a '66, Soverel 28 with the original Atomic 4 (late model). Someone had installed a nice electronic ignition from Indigo (XR700) so I paid for the upgrade to the (XR3000) and put in 2 new batteries.

The carb was brand new and installed by me because I didn't trust the old one. The PO rebuilt the old one several times thinking that's why he was having issues, however, it turns out I found out why later during sea trials. (it was an old and early version and not even the one suppose to be on the engine. Another reason for the replacement.

The engine ran during tests on the stands, and we ran for two hours upriver to our marina @ 1200-1600 rpm which got us 5.5-6 knots. Hull speed on this boat under power is probably maxed @ 6-7 knots. I've never seen it get higher RPM wise than 1800 under load. I have seen as high as 2500 with no load however, I never like taking an engine that high for "no reason". The gauges read erratically, so I replaced those. Decided to run her out at sea to test my handiwork.

Took the boat out for sea trials, and it failed miserably. Just stopped running at @ 1600-1800 on our way back to the dock. I mean it acted like someone turned off a switch. Oil pressure was good and temps were at 140F (RWC) prior to. Tried to start it but it didn't want to start. Turns out I forgot to close the RWC inlet valve at the beginning of this event, and after I had tried to start it several times I did eventually remember to do that.

I suspected I had crap in the tank/fuel system by sighting black crap floating in my fuel. I replaced the tank, fuel lines, filters, and plugs.

Popped the top off the carb and blew all that black crap out of it. Didn't mess with any of the ports, or nozzles. Just popped the top, changed the gasket, put the float back and put the top back on. Used lots of carb cleaner. Put that back in. She ran for maybe 15 seconds and died again.

Changed the oil till it ran clear because it had water in it. 3.75 gallons worth of 5w-30. Finished up with 10w-30 conventional.

Pulled the plugs, and replaced them. Cranked the engine via starter to blow all the water out of the compression chambers with the spark plugs off. Plugs 3 & 4 blew like Ol Faithful. Put MMO in all 4 holes. Let that sit overnight.

Finally found a compression tester. #1@80, #2@45, #3-62, #4-0 or 10. Readings could be way off because of water, however, I am probably wishful thinking. It takes a while for #4 to push my thumb away.

The carb has (or had) a puddle in the intake when I last saw it. Had to put the batteries on charge overnight to continue work on it today. Plugs were left off and covered with a paper towel "to dry out". Got a strong spark, and strong voltage readings that are solid so I've got that going for me. Probably the only thing I got going at this point.

I am hoping someone here can help cause I may be in over my head. I am no slouch in engine mechanics and can turn a wrench. I have been following directions where ever I could find a solution, however, this seems to be boggling my mind. Thanks.

[joe_db]

With compression that low, we are looking at one or more of these issues:
1. Blown head gasket.
2. Stuck rings.
3. Stuck valves.
Low compression equals hard starting, rough running, and low power. A sudden shutdown usually not so much, so there is some other issue as well.

[CaptainCronos]

I am going to pull the carb again and take a look at that. Maybe I didn't seal it good when I pulled it apart the last time. I also put the little clip in on the needle valve/float, and Zenith no longer requires those. Going to pull that out because it might be flooding the engine.

From what I understand, these engines will even run on only 2 cylinders. Once I solve that issue, I can move on with the valves, rings, or gaskets.

[roadnsky]

Just stopped running at @ 1600-1800 on our way back to the dock. I mean it acted like someone turned off a switch.

Agreed we have to improve those compression numbers.
The water incursion has complicated things.
But we should also take a look at your coil too and do a quick test?

Have you visited this thread yet?

[Dave Neptune]

Captain, do you have points or an EI? Either way your shutdown description fits ignition or a failing coil. The coil can work fine and check OK cold and be dead when warmed up~usually 1/2 hour to 45 minutes. Then after cooling it throws a good spark again. May be worth a change.

Loss of power if you have not touched the distributor could be sticking advance weights in the centrifugal advance under the points plate. You can check by removing the cap and giving the rotor a twist if it "springs" back all is well. If it's sticky a bit of lubing will be necessary.

Dave Neptune

[CaptainCronos]

Ok. So the combustion chambers had time to dry out last night. Put the plugs back in. Left the seacock shut for cooling water. Rebuilt the carb and flushed that out. Took that little spring clip off. This time, the engine ran, even with the bad combustion chamber numbers. It seems that the electronic ignition, fuel, and carburetor are good.

It ran at least until I turned on the seacock. Came to a screeching halt yet again. Water is back in the oil and back into cylinder 3 and 4. Talked to Don today. Seems we both are thinking maybe a bad head gasket. Going to take a look again tomorrow after today's adventures.

I intend on drying out the cylinders and maybe doing some sort of crude pressure test on the cooling circuit. It won't fix the sticking valve as it sits, but as long as I have to pull the head off to change the gasket (hopefully that's all that's wrong with it), I might as well "unstick" the valve in the 4'th cylinder.

[CaptainCronos]

Captain, do you have points or an EI? Either way your shutdown description fits ignition or a failing coil. The coil can work fine and check OK cold and be dead when warmed up~usually 1/2 hour to 45 minutes. Then after cooling it throws a good spark again. May be worth a change.

Loss of power if you have not touched the distributor could be sticking advance weights in the centrifugal advance under the points plate. You can check by removing the cap and giving the rotor a twist if it "springs" back all is well. If it's sticky a bit of lubing will be necessary.

Dave Neptune

Electronic ignition.

[CaptainCronos]

Agreed we have to improve those compression numbers.
The water incursion has complicated things.
But we should also take a look at your coil too and do a quick test?

Have you visited this thread yet?

The ignition system has demonstrated itself as being dependable today. It's maybe a head gasket. The engine ran as long as the cooling water is off.

[sdemore]

For what it's worth. I picked up a project boat and rebuilt the motor last spring. It was running great in the garage and when I installed it on the hard. I got the boat in the water last fall and over the winter, it got progressively harder to start and started running rough. I checked it a few weeks ago and had compression numbers similar to yours. I checked the lifters and found two intake valves stuck open. I cleaned them with SeaFoam spray and loaded up on MMO in both the gas and oil. It's been a few weeks and everything is still good. Sounds like deja vu to me...

[CaptainCronos]

Yeah, suspect MMO and SeaFoam and I won't be parting company all too soon.

[roadnsky]

NOT NECESSARILY

The ignition system has demonstrated itself as being dependable today...

Yes, agreed that it may be a head gasket caused by the water incursion.

Turns out I forgot to close the RWC inlet valve at the beginning of this event..

BUT... what caused the original event? That "sudden" shutdown?

Just stopped running at @ 1600-1800 on our way back to the dock. I mean it acted like someone turned off a switch...

As Dave said, "The coil can work fine and check OK cold and be dead when warmed up~usually 1/2 hour to 45 minutes"

[Dave Neptune]

Captain, first check the manifold as it is easy to isolate in place. Manifolds do go bad in time. If the manifold checks OK which I doubt it will then it will be time to check the block.

Enough water to stop the engine is most likely introduced through a breach in the manifold as it can get to most cylinders. However a breach in the block would likely be a cylinder wall and only wet one cylinder.

When checking the block if you do leave the plugs out. This way you may hear air escaping indicating the head gasket or breached cylinder.

Dave Neptune

[CaptainCronos]

Yes, agreed that it may be a head gasket caused by the water incursion.

BUT... what caused the original event? That "sudden" shutdown?


As Dave said, "The coil can work fine and check OK cold and be dead when warmed up~usually 1/2 hour to 45 minutes"

For now, I have no choice but to assume that the coil is good because I have seen it working and producing sparks. It is also a brand new coil. I suspect I blew a head gasket on the way in, and that's what cause the immediate shutdown, just like when I turned on the RWC yesterday. Was running good till I did that, even with a bad cylinder.

Too rough for me to look at it today (winds are bit high) but will look at it tomorrow when the winds die down a bit. Got my 4 gallons of oil on hand though when it comes time for that.

[sastanley]

Fellow owners have had persistent issues with coils and EI in the past, but I agree at this point let's focus on the bigger issue at hand which is water where it does not belong. Too bad we don't know if the water incursion is what shut the engine down at the beginning of this discussion, or if the incursion came from overcranking with the RW intake open after that shut down.

Doesn't really matter now, so, I'd follow Dave's (and Don's) advice and check the manifold, and then the block to see if they hold pressure on the cooling system side. You can get a schrader valve that will screw into an NPT fitting, or even clamp a piece of inner tube to a hose barb and then attach a pump/gauge etc for pressure testing.

Good luck with that test and report back. What ever you do, don't let the insides get rusty from water, especially cylinder walls & valve guides!

[CaptainCronos]

The first one is the engine head nuts soaking in ATF/Acetone, and the second one has the MMO puddling in the carb because I added 1 oz of MMO into each spark plug opening. All the nuts have broken free, however with the rain, I was reluctant to pop the top off.