Leaking petrol from carb (SV650 newbie)

Hi!

I bought an SV650 about a week ago, its not my first bike but my first SV650S! Its a 1999 model and it hasnt been used for about 3-4 years, I bought it from a workmate and its only done 13000 km.

Anyway! the bad part, I have an old GSX550 in the garage that i was trying to start and the first night I had the SV in there I could smell petrol, which I thought was from my start attempts on the GSX. Last night the smell was so strong that we could smell it from outside the garage so I went in to check and found a pool of petrol on the floor. Its not "spurting" out, but dripping, and after following all of the tubes I cant find any of them from the tank that are leaking. It looks like its leaking from the front (towards the front of the bike) bottom of the carburettor, but I dont understand why there is petrol in the system at all. The patch on the floor is about 30x30cm and its dripping at about a drop every 5-10 seconds.

I also cannot find any way to turn off the petrol flow from the tank, so I have to try and find some way to drain the tank.

Does anyone have any idea what on earth this could be? Something that has gone dry and cracked from the lack of use? The battery also seems to be dead, so I have to get a new one, it doesnt hold its charge. I have no idea if this can be related at all, is there any kind of electronic tap for the tank? Since I cant find any anywhere else (with off, on and reserve) as you find on most older bikes.

Any ideas guys?

cheers!

[Biker Biggles]

The fuel "tap" is a vacuum thing and should only open when the engine is running.However they can fail and allow fuel to drain down.Dont know if that is your problem???

[Viney]

Welcome to the site. The fuel tap is vaccum operated and should be closed when the bike is not running. To check, pop the tank up (!0 mins work with a couple of allen keys) and check the pipe running to the tank.

Fuel dripping though, hmmm. The tank might be perforated(this only happens on bikes that have been sitting for a long time). The carbs are pretty eay to take off and check over.

Where are you based in the world. Someone local to you might be able to help.

Could be the vacuum operated fuel valve on the underside of the tank.

Its designed to shut off the fuel when the engine is not running but if its stuck open then the fuel might possibly overflow from the carb.

Check your oil level is not over the Max level as the fuel may be leaking into the sump as well.

See this thread

Originally Posted by Viney

Welcome to the site. The fuel tap is vaccum operated and should be closed when the bike is not running. To check, pop the tank up (!0 mins work with a couple of allen keys) and check the pipe running to the tank.

Fuel dripping though, hmmm. The tank might be perforated(this only happens on bikes that have been sitting for a long time). The carbs are pretty eay to take off and check over.

Where are you based in the world. Someone local to you might be able to help.

Thanks for the quick replies! I already took the tank up as you said, I found it in the owner manual and that was the first I did to check the tubes from the tank, they dont seem to be leaking anyway. It seems to come from the carburettor which with the airbox still attached is a pain to get to, but I can start unscrewing things and check. My priority though first is to stop it leaking, so I was wondering if there was a tap, but if its a vacuum tap then i dont suppose there is anything I can do to manually turn it off, so I can drain the tank instead.

I am in Sweden at the moment, so I have no idea if there is anyone from around Linköping that knows about the SVs. I dont think its hard to know more than me at the moment about these bikes

Thanks!

Originally Posted by RatchetJob

Could be the vacuum operated fuel valve on the underside of the tank.

Its designed to shut off the fuel when the engine is not running but if its stuck open then the fuel might possibly overflow from the carb.

Check your oil level is not over the Max level as the fuel may be leaking into the sump as well.

See this thread

Is there any way I can "force" it to shut off?

[fizzwheel]

Originally Posted by airwalk

Is there any way I can "force" it to shut off?

If the fuel tap is broken then fuel will keep flowing out if till the tank is drained.

It happened to me and it filled the sump and airbox with petrol it leaked out everywhere and I couldnt start the bike because it hydraullically locked the motor.

You could clamp the fuel line to stop it leaking continually.

But if it has failed then replacement of the valve is your best bet.

Originally Posted by RatchetJob

You could clamp the fuel line to stop it leaking continually.

But if it has failed then replacement of the valve is your best bet.

Cheers!

I will empty the tank into some containers. As I understand I can take off the pipe to the fuel pump and see if petrol runs through (before emptying the tank) which should let me know if the vacuum is busted.

Thanks for all the help!

Okay!

Now I have removed the air filter, there was some petrol in the bottom of the box, and when I loosened the screws around the jubilee clips and got some petrol out of it. Removing the tube to the fuel pump also resulted in some petrol flow, and also the vacuum tube to the vacuum fuel valve.

The battery was not dead as I origionally thought, so the only way I can explain this otherwise is that there is petrol in the cylinder which would cause hydraulic locking, am I correct in my assumption?

Also the oil smells like petrol and is thinner than normal.

So a few questions if anyone can help me Mostly to make sure its not a case of "for the love of God DONT DO THAT!" moment.

1) I assume there is no point trying to repair the vacuum fuel valve. I can just buy a new one and replace it, correct?

2) This must have been going on for at least a week or so, since it became increasingly hard to start the bike, it only took a couple of turns before it started, but it /sounded/ like the battery was having a hard time turning over the bike, until wednesday when it just started clicking. i plan to :
2.1) replace the vacuum fuel valve with a new one.
2.2) Replace the oil in the system first with some cheap oil to flush out the system. giving it air in should get rid of the hydraulic locking problem?
2.3) Remove the spark plugs and let the engine turn over to flush the petrol in the cylinders out of the system, and also allowing the new oil to run through the system
2.4) Replace the plugs and change the oil again to some good oil.

anything I have forgotton? Do I specifically have to check any more tubes or clean out the ones that were previously filled with petrol?

3) Is there anything else I ought to be worried about relating to this? Anything that could have gone badly wrong during the few days and 20 or so KM I have driven the bike? Something I can check? Obviously my worst fear is that I have broken something from not knowing about this problem. and I would prefer to get it sorted now than the engine explode in a few months.

4) Is there anything else that anyone can reccomend checking due to the fact the bike had been standing a few years? I would prefer to not have to go through something like this again

5) Is this a common problem with the SV650? is there anything I can check regularly to make sure its not going to happen again?

Thanks!

And btw, what a great forum