Dirty tank -- Inline fuel filter a bad idea?

[tzzzel]

Hi. I left my bike sitting for about 3 months during the summer. Bad idea. When I tried staring it up, it showed major signs of clogged carbs. Bad idle, dying when throttled, low rpm on choke. I was told to clean the tank because my small jet kept getting clogged even after a clean of the jet. I instead tried an inline fuel filter. The one I have is a bit bigger because it fits the 5/16 in hose . I put it between the petcock and carb inlet hose. The openings of the filter are long, so I I had to extend the hose so there would be no awkward bends. Take a look. The tape is to keep the fuel filter away from hot engine.

The issue is that when I tried to start it up, i didn't see the fuel moving. The prime works, so the tank is on, but when I hit the elec start, I don't see fuel movement. Is a hose clogged? Is my hose too long?

Help?

[bumpy]

I have thought of running a small inline filter myself, but haven't really found anywhere that I could mount it away from the heat, and not having it look like a complete mess. I have seen on a diagram that they have a filter somewhere, but think it's more as a breather filter. i'll throw up a link. Part 71

https://bluecitymotorcycles.com.au/oem/suzuki/search-part?brand=suzuki&year=2004&model=2159&section=113485

[Watcher]

Its actually really difficult to see the fuel moving, it may very well be flowing but appear as if the fuel is just vibrating or less.  The GSs don't exactly consume a lot of fuel, so it's less a flow and more a drip, unless you have empty carbs and are on Pri.  The "first fill" will definitely be observable.

I actually have a pretty poor relationship with fuel filters.  They keep clogging unexpectedly and causing odd running issues.

For example, one of my GSs would frequently act as if it was running out of gas with a full tank, and usually it would be happy to run again once it sat for a few minutes.  I went up and down the bike troubleshooting until I was certain it was fuel related, and even after eliminating the vacuum petcock, giving the carbs a once over, and ensuring the tank was breathing properly, the issue persisted.  I eventually traced it back to the filter, and replaced it with a new one, to which the issue was solved.  However, a month or two later the problem came back.  This time I just ran new lines and didn't include a filter, no issues at all after that.

My current Ducati also got the same problem, it would act as if it was out of fuel when it wasn't.  It started happening only a month or so after I got it, and the first thing I did to remedy the issue was remove the filter.  It's been probably 6 months since and I haven't had it happen again.

I'm wondering if my high-speed fuel starvation issues with my first GS, which I never truly solved to 100%, was the result of an overly restricting or fouled fuel filter...

At this point I'm peeved against them.  I feel that the in-tank screen is more than sufficient to prevent particulates from messing with the petcock/carbs too much.  Then again, I ride so darn much that I potentially will never see any rust forming in the tank, nor do I have gas sitting in the carbs long enough to leave deposits, but also perhaps I foul out filters extra quickly because of the sheer volume of fuel flow they see compared to the average, so maybe I'm a rare case where it's more a hindrance than a benefit.
Either way, my suggestion is to clean out the tank proper (take it off the bike) and run as simple of a fuel-line setup as you can.


If you do want to run a filter, I suggest mounting it as close to the petcock as you can.  That is plenty away from the heat and typically hidden by the frame so you get a cleaner look.

[Suzuki Stevo]

Inline Motorcycle Filter: Good, uses gravity
Inline Automotive Filter: Bad, needs a fuel pump

[ajensen]

There are ways to clean out the fuel tank; you can look them up on Youtube. If the tank is good and clean, you do not need an extra filter. I have read on this forum that some people have trouble with in-line filters. Best wishes.

[Endopotential]

Can't quite tell from your photo, but check that the filter isn't tilted upwards too much else you may just be sucking air into your carbs, or get some sort of air lock.

Maybe shorten up the lines to get rid of all the kinks.  Make sure that filter is full of fuel and get all the bubbles out, then connect to the downstream tube.

[Joolstacho]

Agree with all of the above. Avoid any chemical tank liner like the plague!

[tzzzel]

Thanks for the advice, all. I think I will re-consider the inline filter placement or remove it completely. I definitely think I will need to clean out my tank though. I put fresh gas in, but it comes through the filter brown. I hear vinegar is good. Anyone know how to dispose of old gas? Just evaporate it?

[mr72]

Anyone know how to dispose of old gas? Just evaporate it?

To get the old gas out of the tank, first remove the tank, then drain all of it that you can through the tank petcock.

To get the remainder of gas out, you will need to be creative. Use a pump of some sort to remove the gas (not a shop vac unless you like explosions ... a manual pump) using a tube through the filler. Once you get all of it out that can be pumped out or removed with something like a turkey baster or a turkey injecting syringe with a piece of fuel hose on it, then you will have to do something like putting a sponge on the end of a string and drop that in. Be careful to test the sponge first to make sure gasoline doesn't dissolve it.

Then once it's mostly empty and you have only drops left in there, you can let it sit with the cap off for a while and let it evaporate out. It will evaporate eventually.

You will have to go through the same rigamarole after you clean it to remove the cleaning fluid whatever it is.

BTW if you ever had any thoughts of doing repairs like filler or paint to the tank, DO IT NOW while you have the gas out of it. Clean the inside of the tank then do filler and repaint it before mounting it back up. It will save a lot of work. It's much harder than you might think to get the gas out of those tanks.

[Joolstacho]

I'd flush with kero a few times, and then finish with a flush of petrol.