Spring startup problem. Fuel pump?

[WesHeald]

Hi everyone,

I have a 1974 Atomic 4 with a mechanical fuel pump. My engine was running well in October and November after I bought the boat and installed a new carburetor, new seawater pump and a new high capacity alternator. The boat was stored for the winter in the water in Atlantic City NJ. I followed the winterization procedure as far as antifreeze and miracle oil in the crankcase and upper cylinders, but did nothing to the fuel system except add stabilizer to the fuel.

This spring, with my seawater valve closed, I've tried cranking the engine but to no avail. My fuel shut-off valve is open and I confirmed that fuel flows out of the fuel filter just due to gravity. The fuel bowl looks full and clear. When I pull the fuel pump primer arm, it seems to pump a bit of fuel on the first pull, and then takes some time before it returns to where I can pump it again. Is this normal?

I tried starting fluid today and it runs for a few seconds each time, so I don't think that it's valves, or ignition. Should I be looking at my fuel pump or carburetor?

[Clucas]

Welcome to the forum! This forum is a tremendous resource and there are lots of incredibly smart people here. Not sure I'm one of them, but the following is from first hand experience.

A couple of things I'm stating here are obvious safety recommendations -- nothing implied, but we don't know each other.

Couple of things to try.. First, do you have a Moyer Service and Overhaul Manual? If not, order one! Sounds like a fuel problem. First, verify the fuel petcock is open. I would try emptying the sediment bowl (empty it into another container, not the bilge). Check the sediment bowl gasket to make certain it's in good shape. I had one disintegrate (ethanol?) which caused issues. With the sediment bowl on or off, try the priming bail again and see if it is moving fuel (if you're doing this with the bowl off, use a small container to capture fuel). The bail should not be sluggish to return as you describe. If it's still sluggish, I might guess one of the valves inside the fuel are stuck. To get at them, you'll need to remove the fuel pump and open it up (do it over a small box and be careful not to lose any of the springs, caps and bits). You may want to order a rebuild kit (Product No. - FPMP_13_320) so you can replace gaskets while you're there. There are two dime-sized valves in the lower half and a retainer clamp over the two. Note their orientation for when you reassemble -- the valves are identical, but one face up and the other faces down. The valves are a little delicate but can get stuck over an extended period (shellacked fuel?). A small screw driver poked inside will free them up. The rebuild kit includes replacement valves if you just decide to replace them. While you have the fuel pump open, verify the integrity of the diaphragm also and replace if necessary (also in the rebuild kit). The rebuild kit also includes step by step instructions.

While you have the fuel pump off, replace the mounting bolts with allen bolts -- a lot easier to get the fuel pump on and off.

While you're overhauling your fuel system, do you have a polishing filter installed before the carb? If no, highly recommended and very inexpensive. If yes, do you know when it was changed? (I write the date in Sharpie on the side and keep written maintenance log)

Be careful about fumes while doing this -- run your blower and and ventilate the engine compartment for a bit before you trying cranking it over again.

Others will chime in with other suggestions and some will recommend a electric fuel pump. Nothing wrong with a mechanical pump, IMO.

[tenders]

You've done a good job troubleshooting the problem to hone in on the fuel system. My guess would be that you added fuel stabilizer to the tank but didn't run it thoroughly through the system, so the fuel between the tank and the engine is mostly unstabilized. If you bought the boat last fall, who knows how how old that fuel was.

To rule the new carb in or out I'd suggest an elegant but barbaric test: run a few feet of fuel hose from it up to the cockpit and hoseclamp a funnel to it, kept level. Fill the line with gas that's been treated generously with Seafoam--just up to the tip of the funnel, the funnel doesn't have to be full--and see if the engine will run. You're basically substituting gravity for a fuel pump for fuel pressure. If she runs, it's the pump, not the carb.

Count me among the fans of the electric pump. It's cheaper and easier to replace, and slightly easier to troubleshoot.

Confession: I treat my fuel with Sta-Bil year round for all my non-automotive engines - A4, snow thrower, power washer. When you're buying gas for these things you never really know how soon or late the last use of the season is going to be.

[WesHeald]

Thanks for the advice. I do have a manual but don't have a polishing filter. I assume it installs on the metal line between the pump and carb? How do I install it? Is this a Moyer part or West Marine? For the moment though I just need to get the boat moved to a yard as I have other work to get done. How do I remove the sediment bowl?

[WesHeald]

Tenders, you're right. I probably didn't run it enough to get stabil through the lines. How do you hook a hose to that metal line between the pump and carb? And what is Seafoam?

[JOHN COOKSON]

Fuel Pressure Gauge!

Another welcome to the forum.
While you are dealing with this problem you might consider a fuel pressure gauge between the fuel pump and the carb. If will give you instant diagnosis if there is a problem with the carburetor or the fuel pump and\or something before the fuel pump. To isolate and the fuel pump and carburetor run a hose from an auxiliary tank directly to the fuel pump. This will bypass the boat's part of the fuel system.
Divide and conquer. I find it easier when troubleshooting fuel and ignition systems to troubleshoot the boat's part and the engine's part separately. This eliminates a lot of guessing and the associated "drama".

TRUE GRIT

PS: As mentioned do buy a copy of the Moyer manual. It is an investment that will pay big dividends.

Edit: Just read you have the manual. Well done. To hook the polishing filter up ditch the copper tube and install barbs on the fuel pump and carburetor. MMI has a filter "kit" that comes with the filter, hose and barbs.

[tenders]

Ah, copper lines. Those can be replaced with rubber hoses and will probably require some simple fitting replacements too (brass barbs). This makes patching in the temporary funnel line (or, potentially, even a temporary fuel tank from the cockpit) much easier. I think we use 3/16 or 1/4" black rubber fuel hose that is rated for ethanol fuel.

I think on my installation I replaced all the copper with rubber except for the little scavenge tube that runs from the throat of the carb.

"Seafoam" is a bottle of fuel treatment you can get at WalMart or auto parts stores. Despite its name it is not a particularly marine-focused product. It's supposedly a fuel stabilizer, but for that I prefer Sta-Bil; I use Seafoam as a solvent in acute situations like yours where something needs to be cleaned out or diluted. I'm guessing it is just some kind of naptha.

But under normal conditions the only stuff I put into my fuel are Marvel Mystery Oil (A4 only; it definitely reduces sticking valves on my engine) and Sta-Bil.

EDIT: oh yeah, the polishing filter, this is just a little inline thing you patch into the (rubber) hose between the pump and the carb. Marine installations require metal filter housings, not glass or plastic, the downside of this being that you can't see what's going on inside the filter. If your current issue is bad fuel in the carb, the polishing filter would not have helped.

And a second for John Cookson's suggestion of an inline fuel pressure gauge. An even easier way to identify with a high degree of certainty whether the fuel pump is working properly and pushing about 3psi. $20 on Amazon, settle for the 0-15psi gauge and do not bother looking for 0-5psi gauges because they do not exist.

(Now, these pumps are made of plastic and we can debate why we are OK with plastic fuel pressure gauges but are not OK with plastic polishing filters...it is possible that the USGC does not in fact approve of plastic fuel pressure gauges.)

[Dave Neptune]

Wes, I'd be looking at the carb. The metal line you speak of WAS quite common in the past. Most all of the metal lines have been replaced by USCG approved fuel lines by now.

The operation of the pump you described is normal. The bail will "stall" when the line and PERHAPS the carb have been pressurized. I say perhaps the carb since it does not run once started with "Motor Crack (either)". This tells me the valves and the timing or spark timing are OK!!!

Now to the carb~if you can look into the throat of the carb do you see any fuel puddleing in the throat of the carb? OR remove the main jet plug at the bottom of the carb and be ready to catch some fuel in a clear glass container for inspection. Check closely for water or just plain ole krud or gooh. If the carb is dry IE no fuel the needle & seat are stuck. Sometimes a light tap with a solid object to the carb will shake the needle loose.

You can also remove the metal line from the carb and actuate the bail to look at the fuel again in a clear container.

If you find that there is any fuel contamination you should replace all of the lines from the tank to the carb and install fresh filters at the same time and unfortunately all this fixes is the delivery as the contamination is still in the tank. This is the reason to test with an alternate tank and NONE fresh fuel.

Hopefully you just have a stuck needle & seat.

Dave Neptune

[WesHeald]

I removed the flame arrestor and there was no fuel in the throat of the carb. I removed the screw on the bottom of the carb and captured the fuel. No water, no crud or goo, but there were some particles that look like fine sand. I was told when I bought the boat that it had sat in the yard for 7 years and there was some fuel tank contamination, but that it had been cleaned up. I put at least 15 hours on the engine last fall, and she was running fine.

I pumped the fuel pump primer a few times, and it feeds more fuel to the bowl. Does this mean my fuel pump is ok? What's the next step with the carb?

[WesHeald]

Update. I just noticed a thin layer of white chalky crud on the inside of the drain plug. Can I take it apart and clean it or am I wasting my time?

[JOHN COOKSON]

I pumped the fuel pump primer a few times, and it feeds more fuel to the bowl. Does this mean my fuel pump is ok? What's the next step with the carb?

Disassemble the carb, clean it up internally, and rebuild it. The problem won't be solved until you can figure out the source of the crud, most likely the fuel tank. You could try disconnecting the line after the fuel pump, operating the fuel pump, and catching some gas in a clear jar and holding it up to the sun to see if there is any visible crud. This would also verify operation of the fuel pump.
The ethanol laced stuff they sell as gasoline these days can do strange things to a fuel system especially if left to sit.

TRUE GRIT

[WesHeald]

Any particular solvents you'd recommend for cleaning it? The carb was new 6 months ago. Am I going to need a rebuild kit? What if I soak the whole carb in some sort of solvent?

[ndutton]

After full disassembly I soak mine in any solvent available such as acetone or denatured alcohol. It's important to clean the tiny holes inside the carb throat too. I use a welder's tip cleaning tool (various sizes of wire) and compressed air. Cleanliness is Godliness.

Also, I didn't recall it being mentioned, be certain the choke is closing fully. If it isn't you don't stand a chance of starting.

[tac]

Fuel Pressure Gauge

Good 0-5 and 0-10 psig gauges do exist at a moderate price,

https://www.dwyer-inst.com/Product/Series%20LPG5#ordering

Dwyer is a manufacturer of very good industrial and commercial gauges. Be wary of vendor/manufacturers that do not specify what process fluid they are designed for, and not designed for. There are materials that will weaken or dissolve in the presence of ethanol or gasoline. If those materials are in a gauge in your fuel line, you might find the gauge (at best) wildly inaccurate, or (at worst) leaking gasoline. Note: The gauge body and lens material can be metal or plastic - BUT, the "wetted surface", those parts in contact with the process fluid, must be compatible with gasoline and ethanol. That means metal guts (hose/pipe connection fittings, bourdon tube, etc).

The Coast Guard has a detailed standard on fuel system design and installation. Neil Dutton has provided a copy here:

http://www.moyermarine.com/forums/showthread.php?t=9280

A good manufacturer will always list, or tell you, what fluids the wetted parts are or aren't compatible with. The below link gives an idea of the compatibility of polyethylene for seals in, for example, ball valves (i.e. fuel shutoff, which also must be USCG approved).

http://www.engineeringtoolbox.com/peh-chemical-resistance-d_329.html

Another consideration often discussed in this forum is damping the gauge needle. With both mechanical and electric pumps, the gauge needle will bounce wildly with pump pulsations. Over time this can damage the gauge. There are three common ways to fix this:

1. Cheap. Insert an orifice fitting to the gauge. Something like .008" will do: http://www.mcmaster.com/nav/enter.asp?partnum=3820K27

2. Expensive. A needle valve. Adjusting the needle in gives a smaller orifice. Turning it all the way in shuts off fluid to the gauge, allowing gauge removal. Again, select carefully: the body and needle seals must be gasoline/ethanol rated.

3. Moderate. A fluid-filled gage. Here a viscous fluid, often silicone, fills the space between the gauge face and lens.

In 1) and 3) you might want to install a small ball valve to allow mess-less gauge removal and isolation.

http://www.mcmaster.com/nav/enter.asp?partnum=4912K2

[BunnyPlanet169]

Wes - another welcome to the forum!

I've had good luck with any of the carb cleaning sprays from your local auto parts store. My standard advice: WEAR SAFETY GLASSES. The carb is like a funky dribble glass and fluid under pressure may squirt at you from tiny holes. DAMHIKT.

Really small music wire (e.g. any one of the first three guitar strings) will fit through the smallest orifices.

Also - the rebuild kit is not too expensive and pretty easy to install, if you get that far into it.