Mickey Feldman, #644
I believe I read somewhere that the diaphram on the mechanical fuel pumps deteriorated over time (due to the additives in modern gasoline? or alcohol?). This eventually resulted in gas finding it's way through perforations in the diaphram and down into the crankcase. Not good! My A4 had an electric fuel pump when I got it, so this info is second hand at best, but if true you will eventually need more than filters to have a safe and reliable system.
The mechanical one requires an actual hole in the crankcase which must be covered with a plate when being replaced with an electric. This will attach using the former mechanical pump bolts. The electric pump mounts on a bracket that may ( or may not ) be attached using the same bolts that hold on the plate. Some people recommend a safety cut-out switch attached to the nearby oil sender, so the pump only comes on when there is actual oil pressure. Otherwise it could run continually even when the engine is off.
Dave Hoyt, #537, Overdraft
Yes, this happened to me some years ago. It was a not uncommon occurrence in automobiles with mechanical fuel pumps. The clue is when the oil level in the engine keeps going up, and the oil pressure keeps getting lower for the same RPMs.
Dana Berube, #99, Jade
I bought the Indigo Electronics Electric Fuel Pump Kit. The kit included everything needed for installation. A blank-off plate with an integral pump mounting bracket made the installation easy.
In-as-much as I installed it at the end of this last season the engine hasn't been run very much. However, after removing the old, tired looking mechanical pump, fragile glass sediment bowl, old copper fuel lines, rebuilding the carburetor, etc.- and replacing with all new hose, fittings, filters and pump - I think this will turn out to be an excellent upgrade in terms of reliablity and safety.
The Moyer pump setup (http://www.moyermarine.com) is good also - but I chose the Indigo. I also purchased the Indigo Oil Filter kit and that made for a neat place to install the fuel pump safety switch.
I have read that automotive pumps are not a good idea for the A4, and I quote: "The original pump fitted to the boat is a 1 1/2 - 2 psi unit. The carb float valve isn't designed to handle higher pressures.
When I bought my boat, a previous owner had installed an automotive Stewart-Warner 7 psi unit and the carb just couldn't handle it. The carb was always flooding and dribbling gas into the engine bilge. It created a very dangerous situation."
Charlie Wineburg, #192, Maltese Falcon
This happened to me the first day I picked up Maltese Falcon, #192, at Philadelphia. We were on our way to NY City, sailing and motoring down the Delaware river. The oil pressure dropped to 2 (it was later discovered that the gauge was off by 10psi...). I inmediately stopped the engine and checked the oil: seemed to be OK. Still the pressure would be too low. I tried putting some more oil, but after a while, the would go off again. So back to the dock. There with the help of the (ex)owner, we checked the oil pressure valve and took apart the gauge: no oil would come out of these when the engine was started. This lead us to think it was an oil pump failure. To cut it short: it was a very expensive repair just to find out at the end (Moyer) that the fault came from gas dripping from the carburetor (not the pump)into the engine block. Now, maybe I didn't understand Moyer, and it was the pump..In any case, was a fairly simple problem, but difficult to figure out.
The mechanical fuel pump is readily removed for repairs. I would not describe it as easy, because nothing is easy when they're so little room to work. The removal, rebuild, and re-installation is fairly simple and straightforward. I seem to recall that the kit costs about fifty dollars.
I have recently discovered a lively list for atomic 4 lovers (and haters). It is available through sailnet.com. Regarding electric fuel pumps: the consensus seems to be that one should avoid the ones at Pep Boys and stick with the ones at Moyer -- Featherman.
A. J. Matthews, # 605, Ay Mon
I have removed and/or rebuilt my fuel pump in the boat more than a couple of times. This included manufacturing my own diaphragm to a complete rebuild.
Old Lyme Marina sells complete rebuild kits for about forty dollars. Check out their website -- http://www.oldlymemarina.com/ for their address and telephone number.
Now I would in no way classify myself as a small fry. I am 6'2: and 230lbs. I have large arms and hands (size 13 ring). As a result, I have take up the Braille method of carburetor and fuel pump repair and maintenance. In other words, I cannot see what I am doing but I still get it done. However, my arms are usually the victim with ore than their share of scratches and cuts. Just make sure that you keep your inoculations (especially Tetanus) up to date.
The bottom line? If I can take care of business without ripping out the engine or some component of cabinetry, anyone can do it.
I have made my own diaphragm. I would suggest that you go to any commercial rubber or rubber products shop and get a small sheet of nylon reinforced rubber. In fact, the best thing you can do is bring in your old diaphragm and have them match the product!
Once you have the product, remove the metal ring from the top of the old diaphragm. You could grind it off flush (it is pressed/moulded on. I originally left the stud and used a die to cut threads in it. From there, I used a nut to fasten the assembly).
Once you have the old diaphragm off, Use it as a template and cut out your new part with an Xacto knife. if you want to get real fancy, use an appropriate sized punch to cut out the holes for mounting.
In my latest try, I left it flush then drilled and tapped into the shaft with a 10/32 tap, where I used a bolt to assemble the new diaphragm. A little Locktite on the threads is always a good idea in the assembly.
Concerning the electric fuel pump mount, I tried the mount on the side of the engine, with the bracket supplied by Featherman. It worked nicely, until I had a problem with the pump.
I have since mounted it on the bulkhead, opposite and above the carb. I can see it, reach it and have room to get to the oil pressure safety switch. I feel better knowing that I can get to it without tearing up my arm and polluting the air with my swearing!
Erik C Jorgensen, #701, Aurelia
I get my rebuild kits from Old Lyme Marina. 860-434-1272. My fuel pump is mounted on the bulkhead and it's a facet.
After some digging I found out that THere are two different models of facet -- one with higher and one with lower pressure. Mine is a higher one, and it leaks a few drops of gas thru the carb after shutting down unless I do my usual procedure of closing the fuel stopcock and running the motor for 30 seconds before switching off, which cures it. It drips despite carburetor rebuilding, cleaning, etc. Pressure seems the only plausible culprit, and Facet does make two types of pump. Mine has been okay and reliable, despite the pressure problem.
Have done this shutdown thing for more than 7 years now, so do not think twice, but I have thought that I should go for a lower pressure pump if I were to replace it.
Mike Lehmkuhl, Renegade #3, ATHENE
When I bought the rebuild from Don Moyer I asked for the electric fuel pump. He fit it in and as I understand it, he generally recommends an electric fuel pump. I am not aware of whether it is high or low (I suspect low) pressure and I don't have a cuttof switch either... but I haven't had a problem with it... Only problem I've had with fuel was a hole in the pick-up tube in the gas tank which, after a season of searching for the problem, I have since repaired.
Take a look at http://www.moyermarine.com/techtips.html where Moyer describes the best of both early and late model features of the A-4 and shows an electric fuel pump installed on a rebuild he did for one that went into a Hinckley.
The electric pump to stay away from is Facet apparently. Moyer installed a Facet on mine a couple of years ago when he did the rebuild. He has since switched to Carter pumps after problems with the Facet have surfaced.... apparently it has some electric as well as pumping problems... I haven't had a problem with mine so I haven't done anything with it.
Mike Crawford, #422
Relative to gas in the crankcase: the rubber diaphram in the mechanical fuelpumps eventually break and gas escapes and ends up in the engine oil. Ithappened on the day I bought the boat and I'm lucky I didn't blow myself up.The nearest marina (I was bringing the boat 180 miles to my home waters)
installed an electric pump.
Larry Suter, #607, Dogstar
My brother rebuilt Dogstar's mechanical fuel pump in '90 or '91. The top of it basically corroded away so it leaked. He had to scrounge through the parts bins of Ricmond Boat Works to get all the pieces needed and had to cut the gaskets himself out of a piece of neoprene. We didn't know an electric
replacement exists.
To get access to the fuel pump we decided to do an iceboxectomy. It's now a great storage area with panels you can remove to get at the engine. That's far more useful than the icebox ever was.
I don't know if it's science, but it was a project. It was during this period that I got passably good at sailing in and out of the birth and started reading about "yolah's".
Bill Bell, #41, Kialoa
The NAPA number for the fuel pump (I use) is 610-1051. About low pressure ignition cutoff switches: I do not use them. As a small boy, I earned my living flying off big boats with flat ports on top; these aircraft did not have such switches. Neither do any of the cars in our family. The last A4 I bought (in l981, to replace my 1959 origonal) had one which was a pain as you had to crank the engine to 40# to get continuity; I removed it to vast improvement. It is a "fix" for a problem we don't have.
Jeff Maher, Kaynee, #30
Ever since launch, Kaynee's A4 has run a bit lame: throttling up, down; shutting down slowly...then running great...until I tried to come home or go through the bridge.
Anyway, I changed and cleaned each carb twice; put in an entirely new gas tank, water-separating filter, polishing filter--and all new fuel line, thinking that an air-leak was the cause of the problem -- and figuring that the mechanical pump, completely rebuilt, was working great because I got healthy spurtage when I cold-cranked.
Before I changed carbs again (figured I must have radically stuck floats) I bought myself the NAPA pump this morning. Inserted into the line, bypassing the mech pump and jury-wired, I got her fired up. No more problem.
The pump was $34: less than the cost of a rebuild kit for the original pump, and a WHOLE lot easier to change out.
I don't know what would make the old pump so unreliable, pressure-wise...there's no gas in the oil...and the diaphragm was looking good three weeks ago. Maybe a hairline crack somewhere in the casting? Idunno.
Never goin' back to the old pumps. KISS