Looking for help. Fuel Tank Diaphragm

[tonynoriega2]

Hi all... coming here for help.

I have, and am in the process of restoring my 1956-1957 Fuel tank...

I am pretty sure it is a OMC/Johnson/Evinrude "Cruis-a-Day" 6 gallon.

You can see in the diagram, that part item # 47 is the Fuel Pump Diaphragm. It has 3 circular holes.

http://www.duckworksmagazine.com/02/columns/max/02/2-6.gif

The one in my fuel pump, does as well.

However, mine has a pressed together set of washers... its all one piece.. Trust me... it is not two separate pieces.

The problem is that no where can I find... (which is why I am coming here for help) a replacement diaphragm with the 3 holes... they all only have 2.

You can see my example of the one I was provided by a local marine shop ... The arrows point to where the hole on the diaphragm sits over/under....



Mine is on the left, and the replacement is on the right. Not going to work.

The washers seems to be an easier fix... I can just order the two washers and poke a hole for the Fuel Tank foot valve and push rod to connect....

However, I do not want to get into the business of trying to cut a circular hole into the diaphragm and just ruin it...

Any guidance? Resources? Thoughts or Ideas?

All of the old vintage online stores, and ebay do not have a 3 hole diaphragm with an attached set of washers....

Lost here....

 

[racerone]

Re: Looking for help. Fuel Tank Diaphragm

Run to your local BRP dealer and ask about part #302563

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

I do not think that is the right part number... Based on this book, part #302563 has only two holes, and a small hole for the washers...
You can see in the diagram in this Google book, that the 3rd hole or valve, whatever it is, does not exist in the photo....

Cheap Outboards: The Beginner's Guide to Making an Old Motor Run Forever - Max E. Wawrzyniak, III - Google Books

 

[F_R]

Re: Looking for help. Fuel Tank Diaphragm

Tony, You got me so confused that I had to go out to the shop and look at a tank. Then I came back in and looked at your pictures again---then had to go back out and look at the tank again.

#1, I didn't have to look on this: In spite of what you think, those washer WILL come off. They are just stuck to that 60 year old rubber. Stick a screwdriver between them and twist. Of course, you will have to make a hole for the pump plunger. If you had bought the 302563, that hole would already be there.

#2, I am 99.9% positive that the hole you are concerned about is not necessary. The upper housing on my tank is slightly different, but nevertheless I think if you look at the cavity in the upper housing, it doesn't go anywhere.

EDIT: Well after reading the link that you posted while I was typing, I'm confused again. I wonder exactly how the relief valve in the lower housing worked. Any tank I've ever seen had the relief valve in the hole right next to the sight gage.

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

(I think the fact that the lower housing unit in the picture is closer to the camera throws off the alignment of the parts... Kind of noticed that myself.)

F_R... my only counter to your #1, is this .gif here: http://www.duckworksmagazine.com/02/columns/max/02/2-6.gif

At the bottom, you can see the note for part #46 (support washers) and #47(diaphragm) "These parts riveted together on later model Cruis-a-day tanks"

I have tried the screwdriver method and it literally just started bending the washer... I guess its all garbage at this point and wouldnt really matter... so maybe ill try soaking it in some thinner, or rust solvent solution to try again... but its tough.

(I also refer to your post here about the part number: http://forums.iboats.com/johnson-ev...pressurized-gas-tank-leaking-fuel-430761.html)

To your second point, I am about 99% in agreement to your 99.9%...(math?)...anyway... you are correct... it doesn't seem to do anything.....but why would it be there?

Tony, You got me so confused that I had to go out to the shop and look at a tank. Then I came back in and looked at your pictures again---then had to go back out and look at the tank again.

#1, I didn't have to look on this: In spite of what you think, those washer WILL come off. They are just stuck to that 60 year old rubber. Stick a screwdriver between them and twist. Of course, you will have to make a hole for the pump plunger. If you had bought the 302563, that hole would already be there.

#2, I am 99.9% positive that the hole you are concerned about is not necessary. The upper housing on my tank is slightly different, but nevertheless I think if you look at the cavity in the upper housing, it doesn't go anywhere.

EDIT: Well after reading the link that you posted while I was typing, I'm confused again. I wonder exactly how the relief valve in the lower housing worked. Any tank I've ever seen had the relief valve in the hole right next to the sight gage.

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

I could be wrong... (dont tell my wife) but the material around the support washers... seems to be a slightly different texture than the rest of the diaphragm... like it was build with a concave shape put into it...and seems slightly "rough" to the touch...

I have to say... this is absolutely killing me...

Its almost like my diaphragm is a cross breed....

 

[racerone]

Re: Looking for help. Fuel Tank Diaphragm

Run to a local dealer that has a gray haired mechanic.----This mystery is easy to solve !

 

[HighTrim]

Re: Looking for help. Fuel Tank Diaphragm

As you found, there are 2 different diaphragms.

The earlier 302563 with the extra hole. This was for the '51 to '57 tanks.

The later, 305715 was for the '58 to '59 tanks. It had 1 less hole.

Now you can use the newer model diaphragms in the later model tanks like you are doing, but not the other way around.

Ill send you a PM re parts.

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

Run to a local dealer that has a gray haired mechanic.----This mystery is easy to solve !

I did, and he gave me that diaphragm.

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

As you found, there are 2 different diaphragms.

The earlier 302563 with the extra hole. This was for the '51 to '57 tanks.

The later, 305715 was for the '58 to '59 tanks. It had 1 less hole.

Now you can use the newer model diaphragms in the later model tanks like you are doing, but not the other way around.

Ill send you a PM re parts.

So are you telling me I CAN use that newer model diaphragm in my tank?
Maybe I misunderstood your statement.

 

[racerone]

Re: Looking for help. Fuel Tank Diaphragm

Have you studied the details of the 2 different styles of diaphragms/ types of tanks ???------Does your tank have a metal primer or plastic button?------Those 2 washers are shown to be seperate pieces in the parts diagram , you dispute this however.

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

I have studied them quite intently ever since I found what kind of tank I had and wanted to restore it.

I has consumed me the past two weeks.

Mine does have the metal primer, or "fuel pump push rod" that passes through the washers and attaches to the fuel line.

I do dispute that the washers are one piece (on mine at least) based on the annotation in the following image: http://www.duckworksmagazine.com/02/columns/max/02/2-6.gif

This diagram, is 99.9% the same as mine...it even has the same finger indention on the side of the actual tank, like mine...with the exception of the washers...its the same.

It clearly states "riveted together on later model". I will try to get a better photo, but when you look closely at the center of the support washer..."the hole"...It does not look like it is two separate pieces... it is smooth and there is no crease, like you would imagine two pieces being sandwiched together.

 

[racerone]

Re: Looking for help. Fuel Tank Diaphragm

I repaired these tank regularly some 40 years ago !----Never had a problem getting them to work again.-------------Try the 302563

 

[F_R]

Re: Looking for help. Fuel Tank Diaphragm

LATER tanks had riveted diaphragms!!!! They also had a plastic push button.

EARLY (yours) does NOT have a plastic push button and the diaphragm supports are NOT riveted!!! The pump stem and nut hold them together. These issues, I am 100% certain, not just 99.9%.

BTW, if we go even newer than that, the diaphragm had a plastic push button, and was not riveted. It didn't have a hole in the center of the supports either. That is the diaphragm you have.

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

I will give it one more shot on the washers and then I am just going to order new ones if I damage them in the process...

If I can separate them and salvage it, I will post pictures so that you all can laugh in my face.

So now my question is... If I use this diaphragm, can I just poke a hole where the fuel rod and fuel line connect?

I really dont want to mess that up and blow the entire rebuild.

LATER tanks had riveted diaphragms!!!! They also had a plastic push button.

EARLY (yours) does NOT have a plastic push button and the diaphragm supports are NOT riveted!!! The pump stem and nut hold them together. These issues, I am 100% certain, not just 99.9%.

BTW, if we go even newer than that, the diaphragm had a plastic push button, and was not riveted. It didn't have a hole in the center of the supports either. That is the diaphragm you have.

 

[HighTrim]

Re: Looking for help. Fuel Tank Diaphragm

Frank,

Just went down to my pressure tank parts supply, and surprisingly, found 1 metal button, early tank that had the extra hole in the diaphragm and discs that were riveted together. Not sure what happened there? As he states, I cannot separate the discs. Very strange.


Every other one I have ever seen had the push rod with the threaded end and the discs were squeezed together with a nut on the end of the push rod. Maybe some type of aftermarket diaphragm that came with the discs on pre riveted? Don't know, but I just saw one with my own eyes. Would not have believed it otherwise.

Tony, how was your push rod attached to the discs?

 

[F_R]

Re: Looking for help. Fuel Tank Diaphragm

Chris, that's what I want to know too. The rivet goes where the metal push rod used to go through. How can you possibly have both a push rod, and a rivet through the same hole??? Ain't going to happen in this world. But I don't doubt you, Chris.

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

I think the term "riveted" is being use a little loosely...

There are not actual rivets, or a single rivet holding the two washers together....

It more looks like it was machine pressed, and had a hole punched right through it...

The fuel foot valve aka "fuel line" and the metal push rod screw together....

Then there is a nut and tiny little washer that seem to hold the diaphragm securely to the push rod or foot valve...

You can kind of see the two pieces in this photo... upper right corner is the fuel foot valve and I believe is threaded, and the push rod (in the plastic container" has the male threaded end...

Frank,

Just went down to my pressure tank parts supply, and surprisingly, found 1 metal button, early tank that had the extra hole in the diaphragm and discs that were riveted together. Not sure what happened there? As he states, I cannot separate the discs. Very strange.


Every other one I have ever seen had the push rod with the threaded end and the discs were squeezed together with a nut on the end of the push rod. Maybe some type of aftermarket diaphragm that came with the discs on pre riveted? Don't know, but I just saw one with my own eyes. Would not have believed it otherwise.

Tony, how was your push rod attached to the discs?

 

[tonynoriega2]

Re: Looking for help. Fuel Tank Diaphragm

I will go home tonight, and make a video of the parts and put them back together so I can show you want I have.

I may or may not help...

I just want to get the damn thing operational.

If that means, I use the diaphragm I was provide and poke a hole in it and buy 2 separate support washers... then so be it.

BUT... if there is an exact replica of my diaphragm out there some where....

I want it.

 

[HighTrim]

Re: Looking for help. Fuel Tank Diaphragm

Chris, that's what I want to know too. The rivet goes where the metal push rod used to go through. How can you possibly have both a push rod, and a rivet through the same hole??? Ain't going to happen in this world. But I don't doubt you, Chris.

Cannot answer that either, mine is already apart. That is why I was curious as to how it would work? Ill show a pic of the diaphragm I found like this too. I have never seen this before, all my other tanks had the threaded rod and nut.