Fuel problem, please help.

[JohnnyO1]

Blue Runner

I kind of had the some problem last year. Know matter what I replaced my primer ball kept on collapsing. It usually would happen anytime after 3000 rpm. I pretty much replaced everything before the motor and now motor runs perfect.

A couple of things that I learned during the process:

1. Just because you have a brand new primer ball it doesn't mean it is working properly. I replaced my primer ball with one made by tempo later to find out they had a problem with them. Went with one made by Quicksilver for Mercury and no problems since.

2. There is something called a anti-siphon valve in your fuel line. Basicly it is a fitting with a spring loaded ball that prevents fuel to return to the tank. If the ball is frozen it could cause a restriction. Usually located after or at the fuel pick up by the tank.

3. The new ethanol fuel has a tendancy to degrade older fuel lines. That being said a piece of the fuel line could have broken loose and caused a restriction. If you replace your fuel lines just remember there are two types. One that can be exposed to uv light and one that cannot.

4. The fuel pick up has a screen in the tube. With the new ethanol fuel removing any dirt in your tank it is possible that dirt could be clogging the screen in the pick up tube. I spoke with a Mercury Rep. at a boat show and he told me to remove the screen as long as I have a fuel filter. Upon removing the screen I noticed some dirt built up on the screen which could have restricted the fuel.

5. I also changed my fuel filter to a racor fuel filter/water seperator. I did this because everything else was replaced. Filter has a clear plastic bowl which is easy to see water building up. I drain it about once a week.

That being said I have a Mercury motor not a Yamaha but I would think that the fuel delivery would be similar.

Hope this helps.

Good Luck!