fuel filters: in-line and external... - Horizons Unlimited

**acjeske** · #1 7 Jul 2007

Any tips on installing an in-line fuel filter? (It's a Honda CTX200, if that matters.)

And anybody have recommendations for what to use to filter really dodgy petrol before it goes in your tank? (Something you pour it through...)

**Walkabout** · #2 7 Jul 2007

For filling the tank just use any bit of fine mesh material such as mosquito netting or muslin stuff; I did it many years ago by draping the bit of material into the tank, kind of wrapped loosely around the filler neck and then taking it out afterwards with any particles trapped in the fine material - then "backwash" the material to get it ready for next usage.

If you have a mossy net anyway it can do both jobs!!

Dave

**Lone Rider** · #3 7 Jul 2007

I use a paper filter that's designed for lawn mowers, fairly universal.

**Matt Cartney** · #4 7 Jul 2007

My bike is not a CTX200 so I apologise if this is not relevant.

I just bought a standard 'paper' in-line filter from an internet parts shop. It's a small plastic rectangular cube and works well. Try to install the filter so that gravity fills the filter housing with petrol as it is possible to get an 'air lock' in the filter which can stop fuel flow. Mine isn't and it caused a few problems till I could get it to fill. Now the syphon effect keeps it full.
I just cut a piece out of my fuel line the slightly shorter than the length of the filter and fitted it. I fitted mine close to the fuel taps (my acerbis tank has two taps).
The first filters I got were car type ones and far too big, I kept having problems with the fuel flowing through them, so get the small ones designed for bikes. The clear plastic housing can sometimes become victim of 'vapour-lock' in very hot climates. This is (if you don't know) where the fuel vapourises due to the heat and can cause similar problems to an air lock or air bubble. I wrapped mine in sticky alu foil to reflect the heat away which comes from the sun/engine. I left a 'window' in the foil so I could see if the filter was full of fuel and if the paper element was getting dirty.
Don't know whether your bike has a fuel pump or not. Some filters are designed to be used with fuel pumps and require some pressure for the fuel to flow so I believe. Mine doesn't so I had to make sure I got filters that would work with the minimum amount of pressure in a gravity fed fuel line.

Hope this helps!

Matt

**DAVSATO** · #5 11 Jul 2007

any offroad store should have a selection of in-line fuel filters, you just snip the fuel line where you want the filter and put it in, job done. a couple of clamps or clips are recommended though.
to fill, pull the whole line out of the carb and point it downward. open the fuel tap till fuel spills out the bottom then clamp the end(fold it over). flick the filter a few times to get any bubbles out then plumb the line back into the carb.

**acjeske** · #6 12 Jul 2007

Thanks for the tips, guys. Got a basic in-line to install and will figure out something to poor through if it gets really sketchy!

**Nigel Marx** · #7 14 Jul 2007

Make sure you put the filter the right way around, following the arrow on the filter usually. A friend of mine spent many hundreds of dollars sorting out an intermittent irregular running problem on his TransAlp only to find it was caused by the paper cone in the $3 filter having come unstuck and blocking the outlet (well, inlet really if it was the right way).

Regards

Nigel in NZ

**DAVSATO** · #8 17 Jul 2007

oh yes Nigel, forgot about that, well done. even the small square inline ones have an arrow on them

**Bossies** · #9 17 Jul 2007

Make sure the filter is not too close to the engine. Some of the fuel will heat up and vapourise inside the filter and create an air lock and it will take your three days of repeatedly stripping out and cleaning the carb before you realise why the bike is stalling the whole time.

**juddadredd** · #10 18 Jul 2007

I carry one of these Mr. Funnel it even takes out the water from the condesation in those 50 gallon drums, you know the kind you find scattered around the third world staffed by 11 year olds. It doesn't cost much is very small and light, and gives you peace of mind second to none, why only have an inline filter and take the chance of nuking your ride when you can carry one of these.

**Nigel Marx** · #11 18 Jul 2007

Quote:

Originally Posted by juddadredd

I carry one of these Mr. Funnel it even takes out the water from the condesation in those 50 gallon drums, you know the kind you find scattered around the third world staffed by 11 year olds. It doesn't cost much is very small and light, and gives you peace of mind second to none, why only have an inline filter and take the chance of nuking your ride when you can carry one of these.

Nice! But how much room does the small one take up? At US$15 for the smallest, it's something worth considering.

Regards

Nigel in NZ