Need Help Tonight - In a sling...

[sailingchance]

Need help fast - in a sling trying to get back into the water. I have tonight to fix the problem. A few days ago I found water in my cylinders. I know where it came from. Backflow from the exhaust elbow (and a broken check valve further down the line). I have fixed that problem. I've pumped the water out of the cylinders, changed the oil and am trying to get this thing to start again. (Was running fairly well before water)

I am on the hard. So thankfully it was fresh water from a bucket. I "think" I got all the water out. Spark plugs dry and no more spewing. But I have much lower compression now. Used to be 90-100. Now 60 in all 4 evenly. I can ALMOST get it to start when I quirt a little ether in the carb. But then sputters out. checking into fuel pump/carb now. But will it start at all with the compression that low?

I have to launch or go back on the blocks tomorrow at 11am. If I go back on the blocks this whole process will cost a ton of money. Been in the sling for 3 days. Tomorrow is my cutoff. Please help.

[CalebD]

Get some Marvel Mystery oil into those cylinders ASAP. Turn the engine over a few times and re-check your compression #'s.

Possible but unlikely (I hope): head gasket failure.

[sailingchance]

Get some Marvel Mystery oil into those cylinders ASAP. Turn the engine over a few times and re-check your compression #'s.

Possible but unlikely (I hope): head gasket failure.

Caleb Thanks! I was WD40 to help water removal and have put about an ounce of MMO in each cylinder. no change. I'm highly doubtful its the head gasket. I've put some blowing bubbles solution around the gasket to see if there was a leak and I cant find one.

Is there at enough compression at 60psi in 4 cylinders to get it to start/run? What about under load. If I can just get this thing 150 yard to my marina next door, I'll be okay. But they wont drop me without a working engine.

[Mo]

If this is a recent water incursion (I am talking days), you likely have stuck valves...directly related to water getting into the top end. In that case, put a shot glass full of MMO down in those cylinders and turn it over...don't turn it over for more than 5 seconds or so at a time then allow the starter to cool down again...as well put you batteries on a charger if not already done. If that water has been in there a prolonged time your chances of freeing things without pulling the head dramatically reduce.

Ether is not an option. Likely you will find the problem in the valves. You can try some oil there a couple of times. Perhaps it will "tighten" or "seal" around the rigs enough to increase compression enough to slap those valves shut and get them moving.

Other options...valves.
-look through spark plug holes and find culprit valves.
-through spark plug holes manually move valves with bent object or an allen key...might work.
-remove side plate and manually move / free the valves
-remove head and remove, clean, reseat valves.

Other causes:
-stuck rings
-manifold broken...that would have let water in the combustion chambers...in such a case, if the water intake is open water will go through the manifold as it turn over and wet the plugs...valve should be shut when trying to start.

When you get this engine running run it GENTLY...don't go revving it hard...let it run for couple of hours dockside as soon as you get it launched.

[sailingchance]

Thoughts on Mo....

Mo, thanks. If the valves were stuck, wouldn't I be getting zero compression in the that valve? (am new to this whole "engine" thing, so correct me if I'm wrong.) I am getting 60psi in all 4. The water was fresh and was only in there for about 36 hours before being addressed with pumps, WD40, MMO and an oil change.

I will say that something new I've dont is add a hose from the overflow plug hole underneath the carb to the hole above the carb in the intake manifold. Previously had flooded the carb with too much fuel and it was leaking out the drain hole below. Maestro Don Moyer recommended the hose saying it should have already been there to bring overflow back into the intake manifold. Dont know if this will affect how the Carb operates. Ran okay beforehand but now sputters out after ether shots. Thoughts?

Assuming I dont have a cracked manifold or failed head gasket, what else could be the cause of low compression in all 4 cylinders. The compression is the same in all 4 : 60psi. I couldnt have equally bad valves or rings in all 4 right? It seems too coincidental, right? I am going to revisit the head gasket with some more bubble solution.

Will this thing even start or run under a light load if all 4 cylinders are at 60 psi?

Thanks

[hanleyclifford]

The compression you show is adequate to run the engine. Don't overlook the possibility the gauge is wrong, possibly compromised by water from a cylinder. No matter. Make certain your choke is fully closed while cranking. Check the usual stuff like plug wire order and timing. Test your spark against the block or other good ground. If the spark is not really fat check point gap.

[Mo]

History on the engine??

One that I ran into a few years back...owner was driving boat, picked up some debris and overheated. It wouldn't start after....compression was low on all cylinders...he had a split block. Don't feak...might not be your problem at all.

Do you have a history on the engine? ...was it your own or did you just pick up the boat?

I agree with Hanley as well...check wiring and you might try to lean the carb a tiny bit as well.

[ndutton]

I will say that something new I've done is add a hose from the overflow plug hole underneath the carb to the hole above the carb in the intake manifold.

Jason, what size is the hose you added?
The scavenge tube it's replacing is by intention VERY small, in the neighborhood of a WD40 spray straw. Anything larger could be a massive vacuum leak.

Try pinching the hose closed for a test. Be sure the choke is fully closed too.

[sailingchance]

The compression you show is adequate to run the engine. Don't overlook the possibility the gauge is wrong, possibly compromised by water from a cylinder. No matter. Make certain your choke is fully closed while cranking. Check the usual stuff like plug wire order and timing. Test your spark against the block or other good ground. If the spark is not really fat check point gap.

Good thought with the gauge. Will check timing too. What do you mean by testing spark against the block. I was using the 'ol screw driver trick with the plugs and wires. Seem to be getting good spark at the cap too.

do you know anything about this return line I've installed or how it might affect the carb?

[hanleyclifford]

The return line does represent a vacuum leak and if you are using too big a tube it could be significant. However, I would focus on that choke making certain it is fully closed while cranking. Don't rely on a cable; disconnect at the carb and look right in to make sure it is closing all the way.

[sailingchance]

Scavenge tube

If it's only supposed to be size the of a WD40 tube, than mine isway to big. I'm using 1/4" ID hose. Will hit the hardware store first thing in the am to address. in the meantime I will try disconnecting. Previously (when it was running) there wasnt even a plug below the carb. it was open. There was a plug in the intake manifold though.

It's really close. I can hear it WANT to start. It getting 99% of the way there and quitting. Choke is closed. spark is good. Fuel seems to be getting through the carb. Air getting through. clean oil. ARRRRGGGGGHHHHHH!!!!!!

[hanleyclifford]

1/4" is way too big for that application. Sounds like you are closing in on the solution. Plug the holes at both ends and give it another shot.

[ndutton]

Previously (when it was running) there wasnt even a plug below the carb. it was open. There was a plug in the intake manifold though.

As I expected. The plug in the manifold closed up the leak. If this turns out to be the cause of your problem you should consider buying a proper scavenge tube from Moyer and once installed re-tune the carburetor. It's a critical safety item.

http://www.moyermarine.com/cgi-bin/shopper.cgi?preadd=action&key=FCAR_13_60.0

1/4" I.D. hose compared to 1/8" I.D. is 4 times the cross sectional area and adds a vacuum leak of corresponding magnitude.

[romantic comedy]

when you take compression reading, are you letting the air out after each test?

[Hiker_00]

Happened to me

I defer to the better mechanics already involved but this same scenario played out for me last year. It took many oil changes to get all the water out. Please take a care here.

Draining the carb and putting a little bit of gas directly in the cylinders eventually did it for me. I actually have a spare carburetor that cleared up my situation the best.

Over the balmy December 2012 my engine's head gasket and studs all got replaced out of worry seen in some of your posts.

Keep working, steady at it. You'll get there.

Tim