Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (https://www.horizonsunlimited.com/hubb/)
-   Honda Tech (https://www.horizonsunlimited.com/hubb/honda-tech/)
-   -   Simple Newbie question - leaking fuel (https://www.horizonsunlimited.com/hubb/honda-tech/simple-newbie-question-leaking-fuel-54478)

MattOnAMotorbike 27 Dec 2010 22:31

Simple Newbie question - leaking fuel
 
Hi, apologies for the naive question, but...

When my bike is on its side fuel leaks from a small pipe at the bottom of the engine. I'd always thought that fuel leaking out was a bad thing! Is it supposed to do this? (And why!)

As a supplemental question, the engine is always flooded when the bike is righted and the bike is a pain to start. Opening the throttle fully rarely works, though bump starting generally does - does anyone have a better solution though?

My bike is a Honda Tornado 250 XR.

Cheers

Matt

henryuk 27 Dec 2010 22:56

Fuel leaking from small pipe when bike on its side - easy one, carb breather pipe, no problems there it's perfect;y normal, the solution is don't lie the bike on its side!

Carbs flooding when the bike is standing is probably a sticking float ale, there are two solutions: take the carbs apart and clean them, esp. anything that might stop the float valve returning; turn the fuel taps off when you stop

Of course if you're bike is fuel injected then I look like a proper tw*t!!

backofbeyond 28 Dec 2010 15:13

Do you mean it leaks when it's on the side stand or when it's fallen over? If it's the latter then, yes it's the fuel in the float chamber coming out of the overflow pipe. It shouldn't be a great deal if you pick it up fairly quickly.

If it's leaking when it's parked on the side stand then it's the needle valve in the carb float chamber sticking open and , no it shouldn't do that. The needle valve is supposed to maintain a constant level of fuel in the float chamber and is designed to shut itself off as the fuel level there increases.

A bit of dirt in the valve or if it's a bit gummed up from the fuel evaporating through standing too long and it can stick open. Either way you need to sort it out as a. leaking fuel costs money. b. fuel coming out of the overflow pipe can end up on your back wheel, and c. if the overflow pipe gets blocked / is overwhelmed the fuel can end up inside your engine with potentially expensive results.

Sometimes just tapping the side of the floatchamber with something like a screwdriver handle can sort out a slightly sticky valve. If not you'll have to take it to bits and clean it. Guess what I've got to do on my bike in the next few days?

I've got an XR600 and if your 250 is anything like it for hot starting / flooded starting (ie a pig!) you need to learn "the system". Once the bike is back upright - 1. turn the fuel off. 2. pull in the decompressor, fully open the throttle and kick the engine over at least five times rapidly. 3. close throttle, release decompressor, turn fuel back on and ease engine just over tdc. 4. kick to start with throttle completely shut. If it doesn't go, ease it over tdc and try a second time. 5. If it doesn't start on the second kick, go back to 1. and start the whole procedure again.

For a cold start you need to add turning on the choke to 4. and turning off the choke to 1. but going round and round that cycle has never failed to eventually start my bike. It can be a bit of a pain though when you're up against a time limit such as stalling it at traffic lights.

MattOnAMotorbike 31 Dec 2010 16:47

Brilliant - thanks guys.

Yep, the bike is a carb rather than EFI, so you're right there. And "when the bike is lying on its side" was a convenient euphemism for "when I've been a tw*t and dropped it again", so the problem was when the bike was horizontal rather than on its stand, so looks like all's normal and I don't need to take the carb apart (phew!).

And a thousand thanks for the ABC on getting the bike started again - that was just what I needed - I shall try it out next time I've been a tw*t and dropped it on its side...

M


All times are GMT +1. The time now is 08:29.


vB.Sponsors