Its not happy

[Wychall]

I would guess that the only difference is that the rate of "slosh" increases as the level falls. For example, if you have a jam jar with residual in the bottom, then you put a small amount of water in and shake. Less effective if you fill the jar.

[itchyfeet]

Slight aside = I can never understand why some folks think that when you get low on fuel (or run out) it causes crud to be "picked up" and block filters etc. To my way of thinking, the fuel tank pick up pipe is at the lowest part of the tank, where any solids will be, so it makes no difference how much fuel is in the tank ?

I think it is based on experience that if you run empty you often have carb problems due to dirt.

If you want reasons why this is my guess, when you have lots of fuel the movement of fluid ( and the dirt) at the bottom of the tank as you drive around is very much lower than if you have very little fuel and it's sloshing around, the small ammount of fuel left then has a very high concentration of dirt.

Get a bucket full of water and stick some sand in the bottom you will notice the sand moves very little as you move it around , now empty nearly all the water and try again.


E D I T ^^^^ beat me to it

[kevtherev]

I would guess that the only difference is that the rate of "slosh" increases as the level falls. For example, if you have a jam jar with residual in the bottom, then you put a small amount of water in and shake. Less effective if you fill the jar.

Nice analogy

Works for me

[ghost123uk]

Yes, I suppose that must be it

A working (main) filter would ensure it wasn't a problem re the carb or pump though

Note to self = how long is it since I checked my fuel filter = never and there is me = keen on preventative maintenance

[itchyfeet]

As you say for dirt to come through implies holes in the filters.

I also wonder how many of the blocked jet problems are caused by deposits built up in the float chamber which never came through the filters. I have seen sand like crystals in the float chamber before, I read somewhere the come from the fuel.

[ghost123uk]

Yeh, Iv'e seen that too.

I am currently helping an elderly neigbour to put his Ducati GT860 back on the road after a long wet lay up. You should have seen the horrid greenish muck in the carbs when I stripped them. Ethanol fuel in the tank Took ages to get it all out with toothbrush and carb cleaner, but then, right near the end, I discovered that very hot soapy water actually did a reasonable job of removing it I did have to poke the jets through, but I used nylon bristles off a brush, not wire !! Should be at the "firing up" stage over the weekend

[kevtherev]

The fuel line is a long thing.. all sorts of things corrode perish and fall into it.
the carb filter will stop some of it.. but it won't stop water.

[Tinker]

I must say, that the whole fuel filter thing seemed a bit far fetched to me also, and when I finally got the funnel filter out from the carb fuel inlet it was partly full of crud of a mineral type (sand?) I did look at the mesh and think how would anything of a damaging size get past (after getting through the first filter). But having cleared this the problem still remained so it must have got past this to a jet in the carb....