fuel not getting through the carb...

[sailhog]

Thanks.

You teased us Wednesday then left us hanging for two days. Looked like you were gonna do that again. I don't think I could take another two days!

Neil, here's another detail to keep you hanging.... the entire process has involved taking the head off not once... but TWICE!

[sastanley]

sailhog...You must get it running as soon as possible...the water in the cylinders is BAD NEWS. It rusts those unprotected metal parts within hours.

Also, you may have water in the crankcase too...you probably need to do an oil change or three to get the water out of there too.

Sorry about your daughter...Mine just came home from college for spring break and we put a new battery in her car, so I feel your pain.

[sailhog]

Gentlemen, the saga continues....

After having run her three or four times for a total of 2-3 hours a few days ago, I got a little water in the combustion chambers after a hard start followed by a compression check (during which I remembered I hadn't closed the seacock).

I pulled the plugs and turned her over in order to blow out all the water. Cylinder #3 cleared up pretty quickly, but cylinder #4 (aft-most) took about 20 attempts. The good news is that she's dry. The bad news is that she doesn't want to start. I think she's sick of me.

Anyway, here's the rundown: I've got spark at all 4 plugs; compression: 95; 70; 85; 75; when I unscrew the bolt at the bottom of the carb (not the main jet, but the one on the bottom) plenty of fuel comes out. Also, when I put my hand over the carb throat with the flame arrestor removed, I can feel the whoof, whoof whoof of suction as I turn her over with a screw driver on the starter. The carb appears to be closing all the way. I've got a new carb cable in to make sure she operates as designed.

One more clue: Ether doesn't seem to work either. Whether I have her fully choked or have given her a shot of ether, all she does is fire a little bit, then nothing. It's as though she's fuel starved. When I pull the plugs after trying to start her, they are barely moist with fuel. Sometimes they're completely dry. I don't know what they should look like, but I'd think they should be pretty dang saturated.

My only theories are she's flooding and I don't know it... or.... I don't know. I'm totally flummoxed.... I'm ready for her to run....

Thanks gentlemen. Whoever figures this out gets to take my wife to the Golden Corral for the all-you-can-eat buffet....

[sailhog]

Shawn,
Thanks for the note of urgency. I'm trying to get her going asap....

By the way, would anyone have any additional methods of drying out the combustion chambers? As stated above, I pulled the plugs and turned her over many times. There doesn't seem to be any evidence of water in the combustion chambers at this point, but you never know. Maybe this is indeed what's keeping her from firing?

Again, thanks everyone...

[sastanley]

sailhog,

what about heat from a lightbulb (shoplight on the head maybe?) - That may evaporate the water in the cylinders.

What is the condition of the fuel? I cannot recall if we've discussed this yet. One option is to get an outboard tank to eliminate the fuel system and connect it directly to the fuel pump, or even directly to the carb inlet (gravity feed..) to eliminate the fuel pump as well. These are just some ideas to get rid of various components to try to figure out why she isn't running.

One more comment...I have become anal about the seacock..I'd almost rather start her without water and then remember to open it than the other way around...water ingest thru the exhaust has such catastrophic consequences, I'd rather shorten the impeller life and replace it every season. - This is even more critical during "hard" or "no" start scenarios..depending on how your boat is set up, it can take mere seconds of cranking with it open to start it backing up.

That's all I got for now..maybe tomorrow, I'll review this thread again.
Spark, fuel, compression, (& some oxygen) is all she needs. Maybe time to go back to basics here.

[sastanley]

we need a running engine again

OK sailhog...a nice fresh cup of coffee, a review of this thread & we're ready to go. How's your daughter? Mine gets her wisdom teeth yanked tomorrow..busy spring break!!

Now, I am just going to lay out my theories & suggestions, so, please don't be offended..I stand by my earlier statement, we MUST get this engine running ASAP to avoid further, or more permanent damage. You've been thru so many different issues now, it can get confusing..let's try a methodical approach here. I will lay out what I think that should be.

First, a couple of comments:

• Set the motor crack aside for right now..I'd wait for Dave Neptune to recommend it again since he has experience with it and 'wet' motors. I have never needed it on my A-4 & it has been wet a few times.
  
• I am not sure about all this repeated head & manifold removal business...It just seems unnecessary to me at this point. If a valve is not broken, and the 4 pistons go up & down, put the head & manifold back on & leave 'em for now..(I think at this point the engine is 'dry', yes??)
  
• It is also clear that we have enough compression for the engine to run, so you can skip further compression tests...especially since they have proven to be problematic and causing setbacks (getting excited about compression numbers & leaving the seacock open!!)
  
• Have you fixed the choke yet? This exercise is fruitless without a working choke..cut the cable, free up the fitting, or whatever you have to do to get it unfrozen. It must function to diagnose start problems properly. "Crack" is not a substitute for a broken choke.
  
• When was the last time the carb was cleaned? Messy problems like this, water & gunk backflowing into the carb, etc., can lodge little pieces everywhere.

Now a couple of suggestions:
If it was my motor, here is what I'd do, in this order:

1. CLOSE THE SEACOCK (I would leave it closed until the engine runs and remains running)
2. Immediately pour an ounce or two of MMO (I use a squirt style oil can with a flexible spout) into each cylinder and turn the motor over for a couple of seconds to coat the cylinders & the valves & guides. Any moisture here makes valves sticky and rusts the cylinder walls.
3. Check the oil on the dipstick. A raised level could indicate water in the crankcase. Milky oil also indicates a problem. If there is ANY evidence of water, pump that oil out ASAP and replace with fresh oil. Once you get it running, we can address this further...for now confirm oil condition and make sure what's there is fresh if necessary.
4. Pull off the flame arrestor and make sure the carb is dry & nothing is puddling in the bottom..if it is not dry, pull it and clean it. FIX THE CHOKE PROBLEM while the carb is off please. As Neil commented earlier, just make it move..we can adjust it by hand if needed.
   
   4 1/2. Your latest confirms fuel is coming out of the carb bowl drain. Does it stop after an ounce or two? If not, the float valve could be stuck. This would likely result in fuel pouring out of the flame arrestor o-ring and puddling in the carb (possible flooding too.)
   
5. Confirm the fuel supply is good...last year's fuel may not be good, even if it was stabilized properly. At this stage, I may try an alternate fuel source like an outboard tank with brand new fuel in it. Maybe pump several ounces of fuel out of the carb into a clear jar and let it sit..we need to see if it separates. Additional review of this thread reminds me you had the engine running just a few days ago, so I moved this to the bottom of the list, but it is still a concern.

After all those are done (I know it is a long list, but we have a big mess to clean up now) I'd fully close the choke, & attempt to start. Once you get it running & it won't quit, open the seacock. If the engine stalls, turn off the key, & CLOSE THE SEACOCK! It is just a habit you'll need to train yourself to get in to so you don't continue to fill the motor with water.

OK, there is my $0.02! Please report back!

[sailhog]

Shawn! Thanks for this most thoughtful and logical response! The choke has been fixed, the carb cleaned as recently as yesterday, the fuel changed twice, the seacock has been closed (I even removed the impeller in order to spare it).

I'll be heading out there again to give it another shot. I'll be reporting back with all the gory details....

I spoke with Capt. Hanley on the phone last night, and worked through a list of possibilities. His principal suggestion: concentrate confirming or establishing a good strong spark. I'm going to put in new plugs and tighten up the points setting, along with a couple of other adjustments...

Please chime in with any additional suggestions -- and the sooner the better, as I'm heading out to the boat soon....

Thanks for taking the time. I truly appreciate it.
Dwight

[sailhog]

This thread is getting longer than I ever hoped it would....

I checked the engine-side ignition at each step, and found no problems. However, when I checked the new plugs, they were bone dry. There was fuel in the carb bowl, but I'm now thinking that I have a faulty electric fuel pump. It produces fuel, but perhaps with inadequate pressure.

When the engine was running a few days ago, I recall having to prime the engine every thirty seconds or so in order to keep the engine running. I thought this was the due to an air leak in the fuel line, but now I'm wondering if it's because the fuel pump wasn't getting it done.... I had assumed that since there was some fuel in the bowl, and that the pump does produce fuel, that it wasn't the culprit. Anyone care to venture a guess?

It isn't spark, it isn't compression, it isn't the carb.... Again, the plugs were dry, dry, dry....

What thinkest thee? Me thinkest the rusted hulk of an old electric fuel pump has some explaining to do....

[ndutton]

Just went through the same symptoms, turned out to be a failed oil pressure safety switch. Might want to jumper the switch terminals and give it a try.

[sailhog]

Neil,
How do you do this? There is only one wire coming from the oil pressure safety switch to the fuel pump. This has been mentioned before, but it's never been explained exactly how to go about doing this...

[sastanley]

sailhog,

I am guessing here since I have a mechanical fuel pump. I think you take a pair of alligator clips (obviously connected with a wire) and hook one to each terminal of the switch...this bypasses the switch's normal function which closes the circuit on its own at xx PSI. Remember however, with the jumper wire connected, the fuel pump is running 100% with the key turned on.

If this works in terms of fuel delivery, you can likely eliminate my step about putting an outboard tank above the carb and plumbing the line directly into the carb inlet.

Keep at it buddy, we are almost there!

[sailhog]

Shawn,
I have fuel coming out of the pump (into a jar) when I attempt to start the engine, so wouldn't that indicate that the oil pressure safety switch is operating properly? If so, perhaps the fuel pump is moving fuel but not at an adequate rate? Thinking out loud here....

[sastanley]

Perhaps, but to really tell I think you would need a pressure gauge in the line.

An outboard tank that can gravity feed directly to the carb would eliminate this outlier. Again, I have a mech. pump so I am not 100% sure on how the electric pump idiosyncrasies work.

[edwardc]

Shawn,
I have fuel coming out of the pump (into a jar) when I attempt to start the engine, so wouldn't that indicate that the oil pressure safety switch is operating properly? If so, perhaps the fuel pump is moving fuel but not at an adequate rate? Thinking out loud here....

I had that exact problem about a year ago. Pump moved fuel, but with no pressure. I have the Facett pump, and the problem turned out to be a stuck check valve ball. It was easily cleared by opening the bottom of the pump and pressing on the ball. It came free with a "click".

[sailhog]

Edward,
Thanks! How do you open the bottom of the Facet pump? Does it unscrew?