fuel filter restriction

[fermin]

I just started the bike after what it has probably been 4-6 years of rest.  Cleaned carbs rebuilt all but the 'choke', emptied fuel tank and cleaned petcock filter.  The trouble is that when the petcock is opened and the fuel filter is installed no fuel runs down the line.  Removed filter, fuel flows down.

Replaced filter (even though the old one had a clean screen and problem persists.

Also, theres no fuel on reserve, but the main tank delivers fuel.  Any suggestions?.

[Bob_Roller]

How does the interior of the tank look ?

I'd remove the fuel tap and see if there are any restrictions there, it's quite common to have problems with these fuel tanks after the bike sits for a few years .

I got an '84 LS last June, bike sat in a garage in Phoenix, for 9 years, the inside of the fuel tank looked like an old car exhaust system .

[fermin]

No, I was surprised it looked good & clean, the fuel was also clean and I poured it into a glass jar to check it.  The filter was also Ok with just a couple of small paint chips.

It flows nicely without the filter and shuts down.  Photo of filter

[montmil]

The fuel lines and filter appear to be new-ish. Have you checked the filter for flow? The petcock is like mine so I do know you can open it up and inspect / clean.   Monte

[fermin]

Thats the NAPA filter which I replaced yesterday, the old one was flatter and just had a thin wire mesh, it was clean, you could easily blow air through......
But when in line no fuel flows through!!!!!.  I replaced the filter with a barb connection and fuel flow returns.

[Bob_Roller]

If you re-install the filter again, loosen the fuel cap, and see if it helps any .

The fuel tank is vented through the fuel cap, and some people have had issues with the venting being blocked somehow inside the fuel cap .

[fermin]

Thanks Bob,

I had to modify the cap as it was stuck on the tank.  After removing I drilled a hole at the base and locked both the interior and exterior parts together with a screw.  I could not separate the cap into its components as described in the posting below.

http://www.largiader.com/articles/gascap/

I'll see if theres flow without the cap on.

[Lucio_Lopez]

try to cut a little the upper hose. maybe there are some air in the portion of it above the petcock. is the old filter smaller than new one?
saludos!

[Yikes]

This may be a long shot, but is the filter installed upside down?  Have you tried flipping it?

[Ed Miller]

I use those Napa filters on my bikes.  They don't always look full of gas, but it always goes through to the carb OK.  I don't know why they don't fill up, nor why they sometimes do.

[fermin]

Yes installed correctly as they have a arrow marked on the body.  Its the strangest thing, new filter, tank with clean gas, petcock removed (twice) opened up and looking good, fuel streams down good from the tank without filter and then stops when the filter is installed.  Removed, blow air through, fuel comes out and back on line.  After doing this a couple of times I can get it to work with the tank on the workbench.  Now lets see if it works with the tank on the frame.

[DanielMc]

I know over here (UK) some people buy and fit small in-line filters that are primarily designed for pumped supply and unsurprisingly don't work at all well with a gravity feed.

[chewy4x4]

Fermin have you tried to prime that filter? Suck some gas into the filter and then connect the lines back up it might just be a air lock. See if this helps.

[Aristotle]

your report is that when you install the fuel filter, the fuel stops, yet when there is no filter installed the fuel flows well.

what about the type of filter used??
Perhaps its the filter that is unsuitable in this particular case with your bike. Have you thought about different filters that can be used in-line??

DanielMc mentioned smaller filters that don't work very well;however, I do have smaller filters ( a different kind)  that do work well in-line and perhaps (it's just a suggestion) that maybe you would need different in-line filters.

The filters that I use on the lines are about 1/2 the size of yours in the picture.

[Bob_Roller]

I think you need to try another type filter, something like this :http://www.itw-fastex-cva.com/images/stories/data-shts/visufilter/8419-00-9909.PDF


Usually available at most motorcycle shops for around $3US .

This is the filter that I've been using for about 4 years now .

http://www.itw-fastex-cva.com/images/stories/data-shts/visufilter/8437-00-9909.PDF


Definitely has prevented the usual fine sediment and the glob or two of water in the float bowls .