Small outboard fuel filter constraining flow?

[TravG]

I have a 3hp Sears Outboard from 1971. It runs like a champ, when it gets fuel. Being that the tank is quite old, I wanted to install an inline filter between the built in tank and the carb, the old one in the fuel petcock had broken. I bought one of those paper filters from the hardware store, installed it, and now I can't get fuel to flow into the carb. I'm 100% sure it's the filter, as the fuel drains from the tank when the fuel hose is removed but doesn't drain through the hose/filter when I remove the line from the carb. Plus, I can blow air through the line.

It will be easy enough for me to switch to a mesh screen type filter, but I'm not quite sure I understand why this is happening. If I fill the tank up all the way, there seems to be enough head pressure to force just enough gas through, but why shouldn't a paper type filter like this allow the fuel to pass through? Any ideas are appreciated.

Google "Universal Lawnmower Fuel Filter" if you want to see what type of filter I had installed.

 

[robert graham]

Re: Small outboard fuel filter constraining flow?

Sounds like the same Sears/Tanaka 3HP I've been running for 25+years. I replaced that not-so-good, sticky little pet-****/filter screen with an all-plastic chain-saw type, much smoother operation, but no filter screen. I don't have any filter/screen now, carb is such a simple, one-jet, one-needle unit, I've never had it plug up. I usually just run the fuel out of the carb at the end of the day to prevent flooding when I pick up the motor for storage. Maybe you can get a filter with a screen rather than the paper element, but not much room under there for a filter anyway. Good Luck!