Fuel leak 900 Daytona

[gfiandy]

Hi, I came down to the garage on Wednesday to find a large pool of petrol under my Daytona. I quickly tracked this down to a faulty fuel tap in which the vacuum release has failed. After much messing arround I managed to empty the fuel tank (not easy when there is no off option and the vacuum shut off has failed).

I found that fuel had leaked out of the carbs and drained into the air box then dripped out of this.
My question is -

1. Does this means the carbs are faulty or can the floats in them simply not cope with the pressure of the fuel with a failed vacuum release?

2. since fuel leaked out into the airbox is it likely that it also leaked into the cylinders, if so should I change the oil in case it leaked past the rings?

I have a new fuel tap on order so hope to get this sorted over the weekend.

Many thanks for any help you can give.

Andrew
____________________
ANDY

[finpos]

What's likely to have happened is that the diaphragm between petrol and vacuum in the fuel tap has failed. So the petrol has gone past the diaphragm, down the vacuum tube and into the carb that way (just look where the other end of that tube goes). i.e. it's bypassed the float valves, which, yes, should have held it back anyway.

Whether or not petrol is in the oil depends on how the how the bike is put together, but it should be obvious. The oil will stink of petrol and there will suddenly be far too much of it.

finpos.

[gfiandy]

Hi,

Thanks for the advice, I should have just thought of smelling the oil to check it. I checked and it was definately contaminated so I have changed it.

Talked to a friend who knows allot about engines on the float chamber thing and aparently this is common as there is not enough strength in the float chamber seal to work without the vacuum in the inlet manifold. So the carbs are designed to work with a vacuum shut off in the petrol tap.

The seal had not split in the vacuume shut off it had just got some precipitate jamming it open. So the fuel hadn't gone back thought the vacuum hose it had drained through the carbs.



Regards,
Andrew
____________________
ANDY