Is there a shutoff valve for 1974 ODay 27 with Atomic 4

[DMendels]

I am having an intermittent shut down problem that seems to be fuel related. I have been touch with Moyer numerous times and they have been enormously helpful, but this question seems to be boat specific. By jury rigging an external fuel tank at the fuel filter and shutting down valve in the line from the boat's fuel tank, I have been able to isolate the problem as being between the fuel filter and the tank. I have two questions:
1) Does anyone have any helpful suggestions as to gaining access?
2) I have read elsewhere that some boats have a solenoid shut off valve at the tank that shuts off the fuel when the ignition is off. Does anyone have any experience with these? Does the ODay 27 have one? If so, does anyone have any experience and/or helpful suggestions? (Ok, I know that's more than two questions, but any helpfuls suggestions would be most welcome)

 

[shemandr]

I'm not clear on whether using an external tank solved the problem.
The A4 is tinkerer's dream. There are after market kits for a variety of improvements.
I think the solenoid shutoff to the fuel tank is part of the electric fuel pump kit - but I'm not sure. It should be easy to determine if you have a solenoid controlled shutoff or Manual.
I had the shut down problem until I removed the tank and had it cleaned at a radiator shop. And,
I had to re-build the carburetor and the fuel pump. All had the orange goo from the ethanol in the gas.

 

[DMendels]

Thanks very much for responding. The carburetor is brand new two weeks ago and installing that didn't make a difference. It will idle forever, but under load stalls out after 20-30 minutes.

The external fuel tank was not intended as a solution. It was just for diagnostic purposes, but would seem to point to the problem being upstream of the fuel filter and that is just the fuel tank, the line from it to the fuel filter and, possibly the shut off valve. I have a mechanical fuel pump and the engine will start again if I use the priming lever, but will only run for 10 to 20 minutes.

As for removing and cleaning the fuel tank, access is huge problem just to get at it and even if I could figure that out (anyone have any suggestions there) I doubt I could remove it without cutting into the cockpit sole or removing the engine. They seem to have built the boat around it. The electric fuel pump has a low oil pressure shut off valve designed so the fuel pump won't pump fuel when the engine is not running, but mine is a mechanical fuel pump and so this would be a different kind of shut off valve.

Thanks again for reaching out and sharing your exprience.

 

[kloudie1]

The tank vent may be plugged . ?
open the tank fill a bit to admit air . If the problem goes away, get the paper wasp/mud dauber debris out of the vent and hose.. worth a look/see.

 

[shemandr]

That's way too simple! No wonder I didn't think of it.

 

[DMendels]

Thanks to you both and I wish it were that, but Moyer came up with that one and even with the fuel cap off, the engine stalls so it doesn't seem to be a venting problem. I very much appreciate the suggestion, though.

 

[twodzusfittings]

IMHO it sounds like a fuel starvation as you say it will idle but stalls under load. I would check from the fuel pump back towards the tank. Is your mechanical fuel pump external? If yes, remove, disassemble, check the diaphragm, clean the one way valves with some choke cleaner and either replace the diaphragm or if not torn, then reassemble. Make sure you evenly tighten the machine screws as not to have air leaking in. See if that helps. Next would be checking any fuel hose connections. If they are rubber, replace to confirm they havent collapsed. Your fuel line, is it 3/16, 1/4 or 5/16. Possibly not getting enough fuel to the float bowl on the carb. Check your float bowl for crap, varnish or calcification. Do you have any filters in line? Clean and or replace. Check the float(s) in the float bowl. They can absorb fuel and not do as they are intended to do. If they are brass, check for cracks. Shake them to see if there is any liquid inside them. Lastly, is it old fuel? Sometimes folks forget that gasoline will turn into varnish and clog lines when it sits for a long time, especially in hot conditions. Just my thoughts of things to check. I'm assuming that an Atomic Four is petrol driven. Mine is an Atomic Universal which is diesel.

 

[DMendels]

Thanks very much and indeed, the atomic 4 is petrol driven. Thanks for the lengthy suggestions, but I just replaced the carb with a brand new one and that didn't make any difference and when the fuel pump drew from t he external fuel tank instead of the main fuel tank the problem went away, so it doesn't seem to be the fuel pump either. The leaking fuel line between the fuel tank an the filter seems to be where it's happening, but I have to figure out how to access that which also brings me back to the question of the solenoid shut off valve.

Very much appreciate the thought that you gave this, though.

 

[twodzusfittings]

The leaking fuel line between the fuel tank an the filter seems to be where it's happening

I must have missed this particular and important piece of information.

You must have air being sucked into your fuel supply. At idle it has low demand. Under load its needs more fuel. Air is being sucked in or there is a vacuum build up. Can you bypass this solenoid/valve?

 

[DMendels]

Thanks. I think you are right and that does seem to be the problem. At this point, I don't even know if there is a solenoid, which is why I put that out there. Judging from the response, no one seems to have encountered one so I am confused. What puzzles me is how I could be sucking air since it is down hill from the tank to the filter so I should have positive pressure in the line, unless there is a blockage. I have to figure out how to gain access.

 

[twodzusfittings]

If there is fuel leaking out of the fuel line, then there is opportunity for air to come in at the same point.

 

[jibes138]

A leaking fuel line on an inboard gasoline engine sounds a bit like a bomb. I've seen a boat explode and burn to the waterline. Luckily the passengers jumped overboard and were rescued. DO NOT RUN THE MOTOR UNTIL IT IS FIXED AND ALL FUMES VENTED.

 

[DMendels]

Whew! And thanks to all for your responses. As it turns out, the problem was a partially plugged anti siphon valve. I was close with the solenoid thought which I read about somewhere and the concept is the same to prevent a leaking fuel line from filling the bilge with fuel. I have since read that some folks remove them, but it seems that they are coast guard required and I rather like the idea of having something there to keep me from ending up with a bilge full of fuel and ending up like the boat jibes138 saw explode. It's a $15 part so that is no big deal, but, as with so many things onboard, the problem was access. I finally gave up and had the yard do it, but once I swallowed the $1,000 bill to replace a $15 part, I am back to being able to smile and enjoy the sail.

Thanks again to all for your input and here's hoping this information helps someone else struggling with the issue.