Author Topic: fuel pump (Read 8198 times)

Rosscoe · « **on:** August 24, 2012, 11:32:17 AM »

I am replacing my old fuel pump along with a filter since I am losing that built in one in the old one and the instructions mention an "insulator" There isnt one there right now but I dont know if it might be stuck to the old motor or if it is even necessary? Jeff? Might it be on my old motor in your garage.

It says "caution" and I dont want to bend the arm on the new pump, since this would move it out from the block. I havent done enough fuel pumps to know.

Rosscoe · « **Reply #1 on:** August 24, 2012, 04:47:45 PM »

I stopped by Tanners today looking for gaskets for my thermostat housing and also was talking to him about fuel pumps too. He told me the differences between Marine and automotive and I dont think this is something boaters should scrimp on. He said that if the pump ruptures, the excess gas is dumped in the carb via a fuel line and basically floods the motor and it should stall. On an automotive type, the ports would dump it in the bilge. No good! Do you guys with the "newer" mercrusiers have a line that connects to the carb somewhere? I'd like to see what that set up looks like if anyone has pics.

Rosscoe · « **Reply #2 on:** August 25, 2012, 07:08:27 AM »

So does anyone have that fuel/vapor line running off of their fuel pump? Where exactly does it dump? Into the carb via a port or just into the top?

Rich_V174SS · « **Reply #3 on:** August 25, 2012, 07:50:40 AM »

When I was using the mechanical fuel pump there was a yellow breather hose going from the pump to a nipple on the back side of the carburetor up near the top just below the air horn. It's required on marine engines and Mercruiser has been including it on all their fuel pumps for years. I don't remember if the early models had it though, I'd have to check to see if my 1967 engine had one. But I've since removed the mechanical pump, installed a block-off plate on the engine and an electric fuel pump wired through an oil pressure switch. I capped off the nipple on the carb.

Rosscoe · « **Reply #4 on:** August 25, 2012, 08:25:53 AM »

Yea thats the line. My original (Carter) didnt have one but whatever I find to replace it will. I can not believe how many variations of fuel pumps there are for a small block chev! Maybe its the location of the ports? Length of the arm? Whether it has that fuel/vapor port or not? I am not sure what specifically I need to be concerned about. Hardin Marine sells one...small block chevy replacement pump. I may go with this unless someone thinks it might not work for some reason.

http://www.hardin-marine.com/p-14025-small-block-chevy-stock-replacement-fuel-pump.aspx

Rich_V174SS · « **Reply #5 on:** August 25, 2012, 08:34:50 AM »

Location of the input and output ports differs on some models because many engines use hard stainless fuel lines from the pump to the carburetor. Length and angle position of the arm too varies with different engines. Some pumps also contain a built-in filter inside a bowl, usually found on the in-line engines. They all should have the vent hose included.

Rosscoe · « **Reply #6 on:** August 25, 2012, 08:43:31 AM »

Yes my original one had the built in filter which I like but all I have seen as replacements say those are for 4 & 6 cyls as you said. I do have a hard line to the carb so that could be a problem with my replacement. Does it have to be a hard line? I imagine so.

Rosscoe · « **Reply #7 on:** August 27, 2012, 04:14:29 PM »

I had finally settled on a fuel pump (the only bone stock one Hardin Marine sells and it is on indefinate back order. ARGH!

Jerry · « **Reply #8 on:** August 27, 2012, 06:31:31 PM »

http://www.seawaymarine.com/

Rosscoe · « **Reply #9 on:** September 09, 2012, 05:34:56 PM »

More issues.

I ended up getting a Holley fuel pump and of course the fitting sizes are not the same as the old stuff but not a big deal. Since I'll be installing a fuel filter/water seperator ahead of the pump, I cut some of the copper out and replaced part of it with rubber. Not a problem on the "in" side, however after I adapted the "out" side with a reducer bushing, the hard fuel line to the carb didnt line up quite right. I tried bending it with a tubing bender and its all pretty messed up now. It started to kink and I couldnt get it to cooperate, so I decided to just plumb that with rubber line too. Unfortunately, the threads on the carb are not the same as the barb fitting I bought and I dont know what the threads are or if I can find one that would fit. I decided to just cut the original metal line and leave a stub sticking out thinking I could just slide the rubber line over it and clamp it but NOOOOO, its too big and will leak for sure.

Anyone have any suggestions?
I did see some rubber lines with ends crimped on, on some web site but what assurance do I have that it will fit the carb?
I was going to have this SOB running today.

Guess the simplest thing to do would be get some smaller rubber fuel line that fits tight over the metal stub and just replumb the "out" side of the fuel pump.

MarkS · « **Reply #10 on:** September 10, 2012, 04:13:36 AM »

I have done the "cut the hard line and slip a rubber hose over it" connections before when in a pinch Ross, but they sure make me nervous! Double clamps are a must IMO, and flaring the end of the hard line out just a little is also something my feeble brain came up with as a good idea......?

Rosscoe · « **Reply #11 on:** September 10, 2012, 05:18:01 AM »

Quote from: MarkS on September 10, 2012, 04:13:36 AM

I have done the "cut the hard line and slip a rubber hose over it" connections before when in a pinch Ross, but they sure make me nervous! Double clamps are a must IMO, and flaring the end of the hard line out just a little is also something my feeble brain came up with as a good idea......?

I may do this to get by for now until I either bend a new hard line or find a premade assembly that will work. I have found them at several places but they all have a 90 degree bend in the end that wont work real well as my line meets the carb parallel with the front of the motor. I'll need to pick up some small line now. Hopefully I wont have to order 2 feet of hose and pay 10.00 shipping. I should be able to get that locally.

Jerry · « **Reply #12 on:** September 10, 2012, 08:15:58 AM »

I have a double flaring tool. You can get a steel line and make it whatever length you want. DON'T USE RUBBER!

Rosscoe · « **Reply #13 on:** September 10, 2012, 11:56:42 AM »

I really dont want to use rubber over the motor but I always mess up trying to bend line. I may try it but the rubber may be short term so I can get this thing broken in.
Is this line basically just like brake line? Different size? Might have to buy a bunch of extra incase I mis-bend it 8 or 9 times.

dorelse · « **Reply #14 on:** September 10, 2012, 12:26:59 PM »

I'm not a metal working expert...but...sometimes it helps to put something inside the copper when bending it so it doesn't kink. Like a smaller rubber line so you can pull it out after bending. I think? they even make a long spring that goes up in there to prevent kinking.

Others have more experience than I...

Jason · « **Reply #15 on:** September 10, 2012, 12:38:58 PM »

Quote from: Jerry on September 10, 2012, 08:15:58 AM

I have a double flaring tool. You can get a steel line and make it whatever length you want. DON'T USE RUBBER!

Why not rubber?

Rosscoe · « **Reply #16 on:** September 10, 2012, 02:05:38 PM »

Quote from: dorelse on September 10, 2012, 12:26:59 PM

I'm not a metal working expert...but...sometimes it helps to put something inside the copper when bending it so it doesn't kink. Like a smaller rubber line so you can pull it out after bending. I think? they even make a long spring that goes up in there to prevent kinking.

Others have more experience than I...

Yup springs are often used, but I have a tubing bender and I think that is suppose to eliminate most of it however, when you bend it wrong like I do and try to straighten it out, it doesnt like that.

Jerry · « **Reply #17 on:** September 10, 2012, 07:32:24 PM »

Quote from: 74GlasCarlSS on September 10, 2012, 12:38:58 PM

Why not rubber?

A- It looks Mickey Mouse

B- It can leak under pressure where it goes on the steel tubing.

C- If you do have a engine fire, It's the first thing to burn and add fuel to the fire.

Just do it right the first time. Throw yer bending tools away. Use your hands a little at a time. A box-end wrench helps, but easy.

Rosscoe · « **Reply #18 on:** September 10, 2012, 08:06:45 PM »

Agreed.
Might be safer doing rubber on a car motor but I'd feel a lot better with a metal line. I'm looking for some and fittings too.

DanR · « **Reply #19 on:** September 10, 2012, 09:06:27 PM »

Now you guys just added another project for me. My dads boat has rubber lines to the carb. I'll have to get to that now! Better safe than sorry I guess.