Mechanical fuel pump rebuild services

[Don Moyer]

Yes, but unless you're experiencing problems (flooding of the intake throat of the carburetor etc.) 5.5 psi doesn't usually present a problem.

Don

[HOTFLASH]

Looking for Allen head Mech fuel pump bolts

Anyone know a source for Allen head bolts to attach the mechanical fuel pump to the engine?

[Bob Grenier]

Allen head bolts

Any good Auto parts center or Home center will have what you need...Just bring your old bolt and match the thred and size.

[Dana Paterson]

Mechanical Fuel Pump Removal

I just removed the Mechanical Fuel Pump from my Atomic 4 this last weekend and replaced it with a blanking plate. Not knowing that it was supposed to be very hard, I approached it from the flywheel side. To put light on the subject, I positioned myself in front of the flywheel and shined a powerfull flashlight through the slot between the spark arestor and the valve cover. This illuminated the front bolt quite nicely. I then reached around the carb with a 3/8" drive equipped with a 3" extension and a 1/2" socket. First bolt off...no problem. I then removed the extension from the drive leaving the socket on the extention and probed for the rear bolt until I found it. Leaving the extended socket on the bolt, I reached back and clicked the drive onto the extension and backed the second bolt out. Again...no problem.

What i want to know, Don, is should I have left the push rod in place when I put the blanking plate on? I saw no reason to do so and removed it and put the blanking plate and new gasket (with sealer) on. Now, I'm thinking about the little hollow spot machined into the pushrod side of the plate and hoping that I haven't done something really stupid. a quick answer would be appreciated.

Where would I be without this site! Thanks.

[Don Moyer]

Dana,

Congratulations on performing a very difficult task with apparent class and dignity which many of would have felt the need to resort to a bit of "colorful" language before finishing. You were correct to leave out the little pushrod. In fact, if you had left the rod in place, it would have pushed out through the thin layer of metal at the end of the recessed area
in the cover plate.

Don

[marthur]

Magic Words

That colorful language I prefer to call the "magic words" because it has helps me through the most difficult part of the job ; )

[keithems]

removed my mechanical fuel pump last nite -- not very hard -- used a 3/8 drive with a 14 mm socket [it's all i had -- but maybe it had just enuf flex to grab the bolt without stripping it?] -- and most importantly -- a 1" extension called a "wobbly" -- one of my favs for when i can't grab a bolt head directly -- also, to be fair -- my c&c 30 has lots of working room -- esp. since i'm rehabbing and removed the plywood sheathing around the engine compartment -- frankly, i may well leave it off, since i always want to be able to get at my engine easily -- and when you hide the engine, u neglect it and they get that pathetic rust covered look [as opposed to the glamorous rustoleum red look mine has ]

ok -- now my question -- i thought my fuel pump was shot cuz the primer didn't move and the line was totally dry -- but once i had it off, the primer moved and pumped fuel out of the tank for me -- so i reinstalled it -- and -- once again, the lever won't move, though i think the fuel is flowing -- motor had run fine, then a few days ago, just quit 5 sec. after start up -- ever since -- nothing -- i also installed a groco 376 fuel filter last nite [says filters down to 3 microns] and pulled the carb and fuel pump drains -- the fuel doesn't look that bad -- so i'm wondering -- seeing as no coughing, misfiring, etc. -- is it really an ignition problem? -- i had loosened the distributor on that last startup [i know, i know -- should have done that after start, not before] but since then i've reset the timing to tdc and tightened it back down....

[rigspelt]

ok -- now my question -- i thought my fuel pump was shot cuz the primer didn't move and the line was totally dry -- but once i had it off, the primer moved and pumped fuel out of the tank for me -- so i reinstalled it -- and -- once again, the lever won't move, though i think the fuel is flowing (snipped)

If you are referring to the manual pumping bail on the mechanical fuel pump: mine would not move when I gingerly tried it before the mechanic arrived to give my "new" old A4 a good inspection after buying the boat. He said it was because of where the crankshaft had stopped. We turned the shaft a bit and it pumped fine. Does that describe your situation?

UPDATE: I later discovered this INvaluable tidbit by Don Moyer: http://www.moyermarine.com/forums/showthread.php?t=827

[ryanmohr]

I too had an explosion of springs and parts when I opened up my pump. I ended up losing one of the spring caps under the engine and can't get to it.

Everything else on the pump is in decent condition so I don't need a full kit. Where can I purchase the little spring caps? Is it possible to pick up a replacement at a local hardware or auto supply store?

[jerrysingle]

Fuel Pump Saga

A few months back I was engaged in the exercise of rebuilding a fuel pump which led to buying a rebuilt fuel pump which led to a leak in the sediment bowl and ordering gasket and stainless bale.

Now I cannot stop leaking from the sediment bowl. The gasket that came with the rebuilt fuel pump leaked almost immediately. Tightening broke the bale threading connection so we ordered the bale and gasket The gasket appears a quarter inch smaller in diameter than the replacement and very hard.

Now installing the new bale and new gasket ... the sediment bowl is still leaking.

Any thoughts?

[ndutton]

Please forgive the wise-a$$ answer but yeah, I've got a thought. Why not drop $40 on an electric pump and be done with it?

[hanleyclifford]

In his own inimitable way Neil makes a very good point. Most of the active members on this forum it would seem have gone the electric route. Mechanical pumps are increasingly expensive to buy or rebuild. The sediment bowl arrangement no longer seems adequate in the age of ethanol. Most of us have resorted to some type of cartridge filter/separator which can be mounted at a place convenient for observation and service. Such units can handle a lot of crud and water. Electric pumps can also be mounted remotely and conveniently: this is a big consideration for those with difficult engine access. Finally, electric pumps eliminate the danger of the dreaded ruptured diaphragm. The Facet and Carter units are the ones we hear most about.

[ndutton]

Apologize again for the crack, I was in a wisenheimer mood.

The reality is we will all eventually go electric if for no other reason than attrition and corresponding lack of parts availability. With regard to the mechanical fuel pumps, they're going the way of the double action 3 spring thermostats - those that prefer them are hoarding their own private stash of replacements.

For some it boils down to a financial choice. How much have you spent trying to breathe life into your mechanical pump? And maybe more importantly, how much sailing time has been lost in the process? For those in the northeast and similar climes, the season is limited and sailing days are precious. Depending on access, switching to an electric pump might take an hour's work, start to finish (5 trips to the parts store not included).

[jerrysingle]

Fuel Pump Saga

Seems we are having overlapping conversations but this thread seems to bring to bear the point you make about going to electric fuel pump and dump the six month project/saga I have been engaged in.

Neil brings up the point of a $40 dollar fuel pump. I really have not seen that as a solution mostly out of my ignorance of the mechanics of changing from mechanical to electric.

Any thread or documentation that outlines the switch?

[sastanley]

<snip>

With regard to the mechanical fuel pumps, they're going the way of the double action 3 spring thermostats - those that prefer them are hoarding their own private stash of replacements.

<snip>

I have no idea who you are talking about here Neil!

So, is the fact that I have (almost) 3 mech pumps and the original Holley double-action thermostat as a spare a bad thing?