Inline Fuel Filter - Air in it?

Is it normal for an inline fuel filter to be half or more full of air? I have one of the clear ones from Z1, like the following:
www.z1enterprises.com/detail.aspx?ID=295

It's always at least half full of air, and it always has different levels of fuel on the two sides of the screen. Sometimes there is more fuel on the carb side. Other times there the fuel level is higher on the petcock side. The way the line travels means the filter is on it's side, probably a 45 degree angle. Is this normal? Or is it being air locked? Are these directional? I never noticed any arrows on it. Will this cause problems?

BTW, it is brand new and not clogged.

is the line after the filter full...i have clear line, i dont know if you do....if it runs o k , i wouldnt sweat it....i checked one of those filters like yours i had in garage and i didnt see a flow mark..i used the bigger high flow ones and they have a direction arrow on them, if i remember correctly........

Any filter I ever used would have the top half full of air and it was never a problem.

I have a cone shaped filter and it has a flow direction arrow. I would suggest giving yours a good check over for an arrow and if you cant find one and she runs good then dont worry.

Thanks guys.

The line after the filter appears to be full.

I forgot to mention it in my first post but the reason I've posted this is that since installing a new petcock (replaced vacuum activated with gravity) and this line, it seems I have periodic fuel problems. I just wanted to make sure that this was either not causing it or if it was a sign of air lock, blockage, etc.

Keith, you mentioned you had a high-flow one, does that mean mine is a lower flow one? Could it possibly be too low a flow and starving the engine?

In the meantime, I may get a new line to run (with no filter) just to see if the problems go away.

Thanks

i had a friend jet my carbs and i bought a new pingle double outlet petcock and i put the in-line filters z-1 calls the high flow ones...i think they come in two sizes and i had to buy the larger because the smaller oneswere out of stock at the time.i just wanted to make sure my bike had no fuel starvation problems whatsoever...z-1 calls them "high capacity"....i honestly dont know if they make a big diff....i havent had a problem though..maybe going from vac to gravity might be part of it?....

I run one with my vac petcock. There is always air on the top side of the filter element. I have no issues running it at all.

As long as you are not starving for fuel I wouldn't worry about it. If you are you may want to try a larger filter.

HerrDeacon, I have used several Z1 Hi flow and standard flow filters and they provide the same flow... only the Hi flow (larger) filter area is larger and therefore should accumulate more debris before starting to restrict the fuel flow.

IMHO, it is a poor practice to run without an inline filter and would advise against it.

Best of success.

Hi HD,

"...and this line, it seems I have periodic fuel problems."

Did you locate the fuel filter below the carbs? If so I bet your periodic problems occur when your fuel level in the tank gets low.

KZCSI

Thanks again guys for the feedback.

KZCSI, the filter is above the level of where the line enters the carbs, and everything flows down, I don't have any upward bends to the line.

Bill, I agree we should all use a filter, but I'm going to temporarily try it without one just to see if my issues go away.

anything that I have ever run clear lines or a fuel filter on seems to have airpockets in them, drove me nuts trying to chase it ..no delivery problems just didnt sit well with me so I put on black lines and let it go...

as far as a filter goes,I thought that was the function of the strainer in your fuel tank??

on my two stroke twins a quality sintered inline filter did cause some restriction to flow, brand new right out of the package,so did the paper ones...so I dont use them on the two strokes but the same filter on the KZ seems to work great?? gravity vrs vacuum??

I took the filter out of the line yesterday and also found a little blockage in the fuel cap vent. Fixed that and the bike now runs amazing! Before it was like it was starved for fuel sometimes. I'm thinking it mainly had to do with the vent blockage, but you never know.

Just happy it's running great now. Only issue I have remaining is the cold starting issue I have.