Fuel contamination

[Ping]

Some of you know my bike's been off the road since monday.

We've finally found what was wrong with my poor Roger and it boils down to contaminated fuel...

Turns out water has been getting into the fuel tank through the fuel cap - I need to seal up all the bits around the inner seal thingy that's supposed to stop water from getting in... :?

Just a thought that peeps with older models might want to check their fuel caps to make sure they're not compromised.

It's the bolt bits (where the screws go in) inside...

Tomorrow I can ride in to work again!!! YAY!!! No more steenkeeng trains. :D

[Grinch]

How did you test that the fuel was contaminated is there a testing kit that you can get or something? What was the clue that that was the problem?

[Ping]

Symptoms: choking and stall under throttle.

So, we started with the basics by checking spark plugs and HT leads. Which were fine (Stupot got a nice shock for his troubles :lol:).

Decided it could be fueling so pulled off all the hoses to make sure there weren't any blockages. No blockages found. Fuel pump worked fine.

Drained the carbs completely of fuel and noticed the fuel that came out didn't smell strong enough and took about 20 mins to evaporate off the paving slabs. At which point we did a little test with a jar, some fresh petrol and water... The petrol sat on top of the water. AHAH.

Emptied the tank into a bucket and there was about 1cm layer of water in the tank which was getting sucked through instead of the petrol. There's obvious water markings around the base of the bolt things in the petrol cap I mentioned in my first post.

:?

No kits needed. Just a sense of smell and sight required. ;)

[iprideaux]

Is the drain hoze blocked or kinked? My old curvey (stop that you lot) has a small hole inside the fuel cap where rain water can drain away through a tube down through the tank and out through a hoze at the bottom of the frame. Some people have had the hoze either clog with road muck or kink when the tank's been lifted.

I had to reroute my hoze to stop it kinking, I wrote a piece about it in the howto section.

[Ping]

Is the drain hoze blocked or kinked? My old curvey (stop that you lot) has a small hole inside the fuel cap where rain water can drain away through a tube down through the tank and out through a hoze at the bottom of the frame. Some people have had the hoze either clog with road muck or kink when the tank's been lifted.

I had to reroute my hoze to stop it kinking, I wrote a piece about it in the howto section.
That's interesting... I'll check mine tonight. Cheers. :)

[embee]

The other problem is that the pipe from the filler cap recess down to the back end of the tank can actually rust through so that water from the filler recess goes straight into the tank. :shock:

I've not heard of a reliable fix for this, though since the alternative is a new tank, I'd have a darn good go at "sleeving" the pipe personally.

To ward off this problem, I fed a string through the pipe (knot one end and blow it through), tied a small piece of rag to the string, and rodded it through with Waxoyl. An occasional squirt down the pipe with WD40 is a good idea. :idea:

[BillyC]

The easiest way for water to get into your fuel, is by air.

No really...

... especially at the moment, we've had some very humid weather. That moist air finds its way into your petrol tank. We get a nice cool night, and the air cools, and can no longer hold the moisture. The water condenses, and settles into your petrol.

One way to minimise this, is to make sure you never leave your fuel tank empty, or at least less than full, over night.


However, check your hoses and seals too! :lol: