pressure tank. how does it work?

[Chris 1987]

I am working on (And failing) a 1955 25hp big twin. I think I have it narrowed down to gas flow issue (see other thread). Today I changed the air and fuel lines from tank to motor. I tried blowing in air hole and couldn't. I then hooked up bike tire pump to nipple and couldn't get any air in (hand it up to about 80 psi). I tried taking out screws to take the top of tank off and couldn't. Suggestions?

 

[REdington]

Hi Chris
Most do away with the old style pressure tanks and add a fuel pump to their engines. For mine I got 2 newer style tanks off of craiglist for $35 and added a $20 fuel pump. There is online info on how to do this.

Rodney

 

[Chris 1987]

Where did u get a 20$ pump. Saw one for mine but it was 80.

 

[REdington]

Here is what some guys use.
http://www.ebay.com/itm/Aluminum-Fu...her_Vehicle_Parts&hash=item4865b77e5d&vxp=mtr

Here is the one I got. It will pump more fuel than the other one I posted. I just caped the the extra line off.
http://www.amazon.com/gp/product/B000GZQ65C/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

Rodney

 

[Chris 1987]

Are both of those sufficient for my motor? Is there anyway for me to fix the tank that I have?

 

[HighTrim]

A 3 barb pump will work if you decide to go that route. Nothing wrong with sticking with a pressure tank either though. Buy one ready to go or rebuild yours. Many options. Rebuild kits available ebay, or sites like vintage outboard dot com

 

[REdington]

I think the small one would work, but to be on the safe side get the same one I used.
You could, but I don't think it worth the time and effort.
Rodney

 

[F_R]

There is nothing wrong with pressure tanks if you have a clean one. You asked how it works. Actually very simple. The motor pumps air through one hose, into the tank, which pressurizes it and that forces fuel up the other hose to the carburetor to keep the motor running. The primer button does NOT pressurize the tank, it pumps gas to the carburetor so you can start the motor, then the motor pressurizes the tank. If you can't blow air into it, perhaps the hoses are switched?? In any case, those tanks are fully repairable. To get those screws out use a hand impact screwdriver. If you are going to be working on outboard motors, that is almost a necessity anyway. Best money you will ever spend on an outboard tool.

BTW, forget that old wives tale, it isn't going to blow up. And any tank, pressure or otherwise, will be a hazard if it leaks.

 

[racerone]

Operating the primer button on the tank pumps fuel into the carburetor.---When motor starts the crankcase compression is fed to the tank as needed to keep fuel flowing to the motor.---Very simple and very reliable system.----These tanks are superior to some of the plastic tanks on the market today !

 

[Chris 1987]

Well... I tried getting the screws out again with an impact and broke one off. Then I got irritated and put nail in air nipple (hoses r not reversed because they r marked) and hit it will hammer, removed nail and it works fine. The problem is... broken screw means Top not completely sealed now and it is leaking pressure. So, I put some liquid gasket where it is leaking. We will see if that helps. Pumping it with a bike pump for now even with the leak it was pumping gas. How much pressure does the tank need to hold to work effectively?