1956 Evinrude Pressure Tank Conversion Questions

[Ohlouie]

I have recently converted my 1956 Evinrude Lark 30hp from pressure tank system to a single line system. I used the rectangle Mikuni pump. I took it out and it worked great for a while putting around then when I gave it full throttle it did great for about 2 minutes and then started starving for gas. After I completed the conversion, I just used the pressure tank as a single line tank and only hooked up the fuel side. I also put a primer bulb in the line. At full throttle, I found that if I kept pumping the bulb it would never starve so it makes me wonder if the Mikuni can't keep up. Any ideas?

 

[cougar1985]

Re: 1956 Evinrude Pressure Tank Conversion Questions

use a regular tank.the pressure tank is just that, a pressure tank! and is not designed for a vented system.you now have a vented system.the conversion was designed for people who wanted to use the more modern tanks of today ,you are basically only 1/2 way through your conversion.the other half is the newer style tank and line.

 

[rjezuit]

Re: 1956 Evinrude Pressure Tank Conversion Questions

To test leave the fuel cap slightly open. There is a vent built into the cap that relieves pressure when you loosen it. You are probably creating a vacuum in the tank. If it works you might try cutting or removing the gasket on the fuel cap to let in air. Rick

 

[1946Zephyr]

Re: 1956 Evinrude Pressure Tank Conversion Questions

Where is the fuel pump actuator line hooked up at? If you used the nipple on the intake manifold, that was once hooked to your pressure tank set up, then this would most likely be the problem. Is your fuel pump actuator line hooked up to your bypass cover?

 

[Ohlouie]

Re: 1956 Evinrude Pressure Tank Conversion Questions

I used the port under the manifold cover. I took off the reed valves and covered one of the ports.