Water In Petrol Question

Biker Jock · Apr 23, 2019

Today, I'm giving the Tiger 800 a really good clean, after riding through the worst downpour I can remember a few days ago. When I popped open the tank filler, I noticed there is quite a bit of water in there. I managed to soak up some from around the lip, but there is evidence that an unknown quantity has made its way down into the tank. I had filled up with fuel just before the downpour, so I'm hoping it's only a teaspoon or two's worth and it won't be an issue.

My question is, how much water getting into the petrol would it take to cause a problem, and how would it manifest itself? Bit of a misfire, difficulty starting? I don't remember seeing rain get in like that on any bike before, but it was seriously heavy rain.

Callumity · Apr 23, 2019

Fuel sits on water so any that got in will already be at the bottom of the tank where you will struggle to see it. Chances are it’s nothing to worry about (how would it have got over the lip?) and you would not draw any into the fuel pump unless running very low indeed.

Alatamoc · Apr 23, 2019

Just a thought ....don't you how your drain works...on my Tiger 955i it runs down a tube on left side of the bike and into a sort of one way valve thingy( technical,eh?).
The valve can block and water then backs up till it pools in the filler cap lip.
I usually check mines still working by squirting , carefully, wd40 into the lip drain hole till I can see it run out on the floor.