Priming

I am posting all of this, not so much as to tell you how to solve your problems on your boat, but just to demonstrate some ways that you might try and to get you to think about how to go about it in your own situation.

This priming tool or thig-a-majig as some would call it is a work in progress. On paper it should work, but frankly it has not been tested and it will be at least a week or more before that is going to happen. There are issues of vacuum leaks from fittings not sealed up properly, whether the fuel pumps, electric and manual will have enough vacuum to pull the fuel. There is the issue about the placement of the pump which is optimized to push rather than pull fuel, whether it should be close to the filter or if being used to pump fuel to the engine from a jug, being close to the jug. There is the issue about the height of the jug in relation to the pump, filter and engine.

I am going to setup a test situation using a jug here at the house and try this all out. I should have the parts for this by the middle of the week.

I have a vacuum gauge and a friend suggested a hand vacuum pump like MightyVac for bleeding brakes to pull the vacuum. I will be adding pictures of the components and how they are hooked up as I get time. Understand that the components that I have selected and are pictured are not the only ones that might work and I have more parts ordered that may be tested in replacing some of the originals. In the long term I am looking for Aluminum parts as they are lighter in weight, but the steel ones that I have been using to start with may be a better choice for you as they may be cheaper and more readily available.

Weight is a big factor in my traveling.

Sealing fittings is best done with o-ring seals, followed by pipe joint goop, followed by Teflon tape. Tape is problematic since tiny pieces can come loose and plug up the lines, goop if not used too liberally is a little less so. I may use tape since my setups are temporary and it is more portable.

In order to test for vacuum leaks you need shut off valves at critical locations. Of course if the vacuum won't hold you then have to track down the leak. Vacuum testing in my opinion is a little safer than pressure testing. To find the leak(s) you will need some fluid or paste or something that can be placed over likely joints, then watch to see if the pressure holds longer.

If you pull a vacuum in place of the engine pump and you don't have any valves shut in the lines leading back to the fuel tank and the vacuum stays up, then the tank vent line is most likely plugged. I have been suspicious of this on at least a couple of boats, but did not have the tools to test for the problem. If you can't clear such a plugged vent line, or replace it, sometimes the venting can be done by removing the fill cap. Of course then you have to prevent water from coming in it!


Mityvac8000 Brake Bleeding and Vacuum Pump



Warning: if all of these half baked emergency solutions scare you then make sure that you have "right stuff" so you won't have to consider any of these crazy ideas! Have the tools, jug of diesel and the spare filters to do it right.


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