White deposits in carb's when stood.

[Grizzly]

This is a subject that has been bugging me for a couple of years now....

When i park my Elan up for any length of time (3 week+) the fuel dries out in the Carb bowls and leaves a white deposit (rubbish UK Fuel), i only put v-power in it as well.

How i usually deal with this is take the top off the carb and suck as much fuel out as poss with a Syringe if i know the car's going to be laid up for any time, this helps but i still get white deposits on the jets etc.

I understand the white deposits are modern additives for one reason or another added by the Fuel manufactures that are left behind when it evaporates off..... it annoys me as i had my car rolling road tuned at Christmas only to find it running like a bag of spanners this morning (all the jets messed up with this white stuff). Next time i lay it up for any time i will remove the carbs and drain them totally but the problem is it doesn't get used that often so i seem to be constantly cleaning the jets.

Any ideas?

[nmauduit]

I'm a bit surprised by the car being recently tuned on a rolling road yet getting out of sweet spot after just a couple week inaction... Is it a really fine powder (such as would be with drying fuel deposit) - which is unlikely to clog jets in such a short period I would think, even getting the fuel valves stuck would take a lot of it, then would likely be washed out each time you run the car again - or could there be some thicker, tackier material with it? that may be something disintegrating over time (esp. because of alcohol that now gets added to most fuels), like a fuel tank inner protective coating...

[Grizzly]

Yep, doesn't take long to clog all the jets up. My car was Dyno'd in December and had sat over the wet months until end of March. When i came to run it wouldn't rev properly and two of the four Pump jets were blocked.... So i had to take the carbs off, strip them and run the lot through my hydrosonic cleaner. Not the first time this has happened, it's happened with cars other than the Lotus's which makes me think its crap fuel.

I didn't take pictures of the white stuff but i've been reading up on it and this picture is very similar to the issue i have. I'm told modern fuel is not designed to dry out in Carbs, some sort of detergent is in it that returns to powered form, one thing i haven't tried is to just let it soak in fresh fuel? Might dissolve??

img_0251.jpg (57.36 KiB) Viewed 842 times

[Grizzly]

Guess the trick is not to leave it stood