Fuel filter

[iggyw1]

One more question concerning my fuel line on my 35 H.P. Johnson motor. I have a 6 gallon portable tank, single hose line. I just had a problem with the gas cap (no vacuum) that you guys helped me solve, and I now added an in-line fuel filter (NOT a water separator, but just a clear glass filter, 10 micron filter). I installed it on the suction side of my primer bulb. When I pumped up the ball 'til it was hard, the filter filled up with fuel. I looked at the gas line the next morning, and the filter was empty, but the ball was still hard. I assume it is because the ball has a check valve in it, correct? I was concerned that the glass fuel filter was empty, then I thought to myself, "even if the fuel filter was not there, the gas line would have drained back into the tank anyway from the suction side of the ball," correct?
Now, when I take the boat to the lake, the ball is already primed, hard, & ready to start my motor. Once the motor starts, I am guessing that the fuel filter will fill up after the motor starts due to suction from the motor, correct?? Or should I have installed the fuel filter on the discharge side of the primer ball so it would stay filled as the primer ball did? Thanks for any insight on this!

 

[dingbat]

One more question concerning my fuel line on my 35 H.P. Johnson motor. I have a 6 gallon portable tank, single hose line. I just had a problem with the gas cap (no vacuum) that you guys helped me solve, and I now added an in-line fuel filter (NOT a water separator, but just a clear glass filter, 10 micron filter). I installed it on the suction side of my primer bulb. When I pumped up the ball 'til it was hard, the filter filled up with fuel. I looked at the gas line the next morning, and the filter was empty, but the ball was still hard. I assume it is because the ball has a check valve in it, correct? I was concerned that the glass fuel filter was empty, then I thought to myself, "even if the fuel filter was not there, the gas line would have drained back into the tank anyway from the suction side of the ball," correct?
Now, when I take the boat to the lake, the ball is already primed, hard, & ready to start my motor. Once the motor starts, I am guessing that the fuel filter will fill up after the motor starts due to suction from the motor, correct?? Or should I have installed the fuel filter on the discharge side of the primer ball so it would stay filled as the primer ball did? Thanks for any insight on this!

Filters go on the suction side of a (fuel) pump. You want to pull contaminants into a filter, not push them through

An in-line rock and stick catcher (filter) should be upstream of the primer bulb and downstream (suction side) of the fuel pump

 

[iggyw1]

Filters go on the suction side of a (fuel) pump. You want to pull contaminants into a filter, not push them through

An in-line rock and stick catcher (filter) should be upstream of the primer bulb and downstream (suction side) of the fuel pump

Thanks dingbat. I currently have it on the suction side of the primer ball (between the ball and fuel tank, down stream). I am going to move it to above the ball, as you suggest I do, which will put the filter between the ball & the motor, (upstream from the ball). However, after running it today with the way I have it set up now, (below the ball on the suction side) It made me wonder if the fuel pump does NOT always suck fuel up to the motor, but only when the carb calls for it??? The reason I am asking this now is the fuel filter that I installed below the ball is glass. I can see the gas inside of it. I can see gas enter the glass filter and go thru the filter element, then it seems to empty back down into the fuel tank, then starts filling again, and keeps repeating this, and this continues as long as the motor is running. I ran it faster than idle today (on muffs) and it did the same thing except more often and faster, so I am assuming that the fuel pump is not always sucking??? Does this sound like a normal operation (what I am describing about what I see in the glass filter)? Seems to run great like this and it just keeps on running, and running, so to me right now, it appears to be normal. Please advise. Thanks for your replies and suggestions!

 

[dingbat]

Thanks dingbat. I currently have it on the suction side of the primer ball (between the ball and fuel tank, down stream). I am going to move it to above the ball, as you suggest I do, which will put the filter between the ball & the motor, (upstream from the ball). However, after running it today with the way I have it set up now, (below the ball on the suction side) It made me wonder if the fuel pump does NOT always suck fuel up to the motor, but only when the carb calls for it??? The reason I am asking this now is the fuel filter that I installed below the ball is glass. I can see the gas inside of it. I can see gas enter the glass filter and go thru the filter element, then it seems to empty back down into the fuel tank, then starts filling again, and keeps repeating this, and this continues as long as the motor is running. I ran it faster than idle today (on muffs) and it did the same thing except more often and faster, so I am assuming that the fuel pump is not always sucking??? Does this sound like a normal operation (what I am describing about what I see in the glass filter)? Seems to run great like this and it just keeps on running, and running, so to me right now, it appears to be normal. Please advise. Thanks for your replies and suggestions!

The fuel pump supplies constant (pulsed) pressure. The needle valve/float assembly in the carb opens and closes to control the flow of fuel into the engine.

So yes, what your seeing is normal operation without an anti-siphon valve in tank

 

[racerone]

Most fuel pumps have a fine screen.----Really all you need.

 

[iggyw1]

The fuel pump supplies constant (pulsed) pressure. The needle valve/float assembly in the carb opens and closes to control the flow of fuel into the engine.

So yes, what your seeing is normal operation without an anti-siphon valve in tank

I will probably leave it before the ball then if it's normal. I know if I put it on the discharge side of the ball. it would probably stay filled then as the ball has a check valve in it.

 

[iggyw1]

Most fuel pumps have a fine screen.----Really all you need.

Yes, my fuel pump has a very fine screen filter built right into the pump housing. I added the glass inline filter just so I can observe the gas flowing thru it for my own personal, visual, satisfaction I suppose, and see if the filter is actually catching any contaminants, but it probably will not do too much really with the fine filter at the end of the suction tube inside the gas tank. If the additional filter causes any problems at all, it will be removed. Thank you for your knowledgeable input, racerone,. I really ALWAYS appreciate it!

 

[tphoyt]

I had one of those glass filters break on me once some time ago. 40 some odd years now that I’m thinking about it. Anyway I had to redo the hose to get home which was not a big deal but it happened during a storm and I was blown up onto the flats. It was only a 12’ boat so walking off the flats wasn’t a big deal until I stepped on a stingray a took a hit to my calf. That made for a real PITA of a day.
I never used a glass filter ever again.

 

[airshot]

Most fuel pumps have a fine screen.----Really all you need.

I agree but with today's fuels adding an extra filter does not hurt anything. I always use clear so I can see if anything is in it. On occasion the inline filter showed gunk and easily changed out and when the pump filter was checked it was clean. I prefer to catch the crud where it is easier to change the filter. Your right not needed, but cheap protection in my book and easier to change out when needed.

 

[dingbat]

I agree but with today's fuels adding an extra filter does not hurt anything.

Statically, using a 10 micron filter in a 30 micron application increases a failure by a factor of 3

A cheap, 30 micron plastic filter used on your lawn mower is adequate for carbureted outboard. Save the 10 micron filters for fuel injected systems requiring a 10 micron filter

 

[saltchuckmatt]

I had one of those glass filters break on me once some time ago. 40 some odd years now that I’m thinking about it. Anyway I had to redo the hose to get home which was not a big deal but it happened during a storm and I was blown up onto the flats. It was only a 12’ boat so walking off the flats wasn’t a big deal until I stepped on a stingray a took a hit to my calf. That made for a real PITA of a day.
I never used a glass filter ever again.

Yeah.....sounds like a fire hazard too. No glass filter housing for me thanks.

Don't you just love memories like that, I don't think anyone's "Mama" would allow that today!

 

[tphoyt]

I was out boating solo when I was 10. I put my poor mother though hell looking back.
My daughter is a pilot and started flying at 13.
I remember very clearly when she took her first solo flight at 14.
I was terrified. She had her pilots license before her drivers licenses so now I have nerves of steel.

 

[iggyw1]

I was out boating solo when I was 10. I put my poor mother though hell looking back.
My daughter is a pilot and started flying at 13.
I remember very clearly when she took her first solo flight at 14.
I was terrified. She had her pilots license before her drivers licenses so now I have nerves of steel.

Interesting, but really has nothing to do with the subject matter of this thread, does it? Should have started your own thread somewhere to posting this info.

 

[saltchuckmatt]

Interesting, but really has nothing to do with the subject matter of this thread, does it? Should have started your own thread somewhere to posting this info.

Ease up....really?

 

[iggyw1]

Interesting, but really has nothing to do with the subject matter of this thread, does it? Should have started your own thread somewhere to posting this info.

Sorry, Should not have posted this. I was out of line.