Mech. Fuel Pump Blockoff

[Liqui-Fly]

Converted a Merc 200 carb to run off a Holley red and have the mechanical disconnected. Does anyone have or make a blockoff plate so I can completely remove the pump? If not what is a good method to clean it all up? Holes that do nothing make people nervous.
David

[MadMat]

Good question, I'm just doing exactly the same.

I was either going to make a plate to mount using the fuel pump holes to cover the hole in the block and maybe make it a junction point for the carb feeds, or put the fuel pump back on with a solid plate in instead of the diaphragm (also removing the spring and possibly the one way valves) That way also means no scratching around for tees and reducers.

I'd be interested to hear other peoples views too.

P.S. I have the diamond shaped mechanical pump, not the square.

[Liqui-Fly]

I was thinking of gutting it also and using the existing gasket and blocking the entire thing off but I really don't want to make a plate and am not sure how much to pull out of the guts.
David

[Rickracer]

$7.00 + shipping.:cool:

[Greg Moss]

David, There really is only two holes you need to worry about. All the mounting holes are blind so the ones to worry about are the pulse holes. The one under the fuel pump I tap and screw with lock tight a 1/4 20 screw. There is another that had a hose going from the fuel pump and the block that is 1/16" pipe I just get a plug and screw it in to the block. like I said all the mounting holes are blind and do not penitrate the block.

[Liqui-Fly]

Rick is that a fuel pump block off or an oil injection block off? Moss man I'm going to take a look at what you're saying. Thanks.
David

[Rickracer]

As usual, Greg is right. That was an oil pump blockoff I was talking about. I'd do what he says, and tap and plug the pulse hole. I've done the same to my OMCs. Sorry about that, :cool:

[Liqui-Fly]

The dude buying it decides he wants to go back to oil injection?
David

[Greg Moss]

Remove the plugs and reinstallo everything Ifyou saved all the partsLOL

[Liqui-Fly]

I haven't had one apart if ya can believe it. Ya propbably can. Isn't the bladder open to the crankcase?
David

[Rickracer]

..and then, just to be on the safe side, vacuum out the hole. :cool:

[Superdave]

Tap the hole & put in a stainless steel setscrew. Worked for me!
Dave

[Greg Moss]

yuo really want a Screw with a head on it. I am a firm believer in **** happens and a set screw with out a head has a chance of working loose and ending up inside the motor. The head will only let the screw go so deep

[Markus]

Does it hurt to have the diafragm pumps connected when using an electrical fuel pump? I have seen it done both ways.

[Greg Moss]

but why have both? The diaphram pump is a point of failure. If you disconnect the lines to the pump and just leave it there the diaphram with out fuel on it will over heat and break then you have an air leak and you know what happens next. If you are going to run a electric pump I would remove the diaphram pump and block the ports like I said before.

[Rickracer]

If you push Xlbs of fuel pressure to the manual pump (which is supposed to operate off of atmospheric pressure) with the electric, you may wind up with too much fuel pressure. Been there , done that. :cool:

[Liqui-Fly]

Me too and she ran like a fat pig of a mota and ate gas too.
David

[Superdave]

You don't go all the way through. You only tap 1/4" deep with a bottom tap. Use locktite and the setscrew will bottom out where the threads stop. I mounted my regulator where the fuel pump used to go.

[Liqui-Fly]

I hope to accomplish this this weekend. Needed an excuse to buy a tap an die set anyway.
David

[Liqui-Fly]

But the bottom hole is linked to a fitting which is hooked to a hose that runs to the bottom of the crankcase. Is this to get lube to the lower bearing? What do I do with it?
David

[Greg Moss]

The bottom bearing is a small hose that runs up the starboard side of the front of the motor. the one you are looking at should have a 1/16" pipe fitting in it. that needs to be pluged.

[Liqui-Fly]

Sorry for being slow I just don't want to screw anything up. Plug the upper hole where the pump was and then plug down low where the hose runs from the block to the fuel pump? What was this hose for?
David

[Liqui-Fly]

The hose looked like 1/4 or 1/8 inch.
David

[Greg Moss]

it takes 2 pulses to work the fuel pump. One comes from under it and the other one come in the hose. You must plug both or you will have an air leak.

[Liqui-Fly]

Read what you said the damn first time agin then I wouldn't have asked three more times. Thanks for your patience. No coffee this morning.
David

[Greg Moss]

Now get off the computer and head to Starbucks LOL

[Liqui-Fly]

The larger of the two bladders was torn. It rested right on the return spring. Was this the design or was it put together wrong? Would that effect performance if the pump was disconnected?

David

[Greg Moss]

There should be a plastic cover between the spring and the diaphram. If the diapram has a hole in it it is getting fuel to flow straight into that cylinder. Or if the pump is bypassed it will leak air. Either way it is not good for the motor.

[Liqui-Fly]

But it was a gas hog and driiped like a mother out of the exhaust at the end of the day. All this time and I never got into the fuel pump. Motor would flatten right out at 6 grand...I just figured that was all she had. Man this 260 is gonna be a big suprise hehe.

David

[Liqui-Fly]

Don't add more please.
David