03 sv650 running problems

i have a 2003 sv650s and it has recently had a couple of problems, first it wouldn't start but that was just the spark plugs needing replacing, so i replaced the plugs and it fires up, but it has a sound coming from under the tank somewhere, it sounds as if its a air leak to me (hissing noise) and its not a constant noise, it goes with the rpm of the engine (on and off about every second). and also if i rev it slightly the rpm will go up alot more than it should and stay at that rpm for a second or so even when the throttle isn't turned.
it has had a new battery fitted and the plugs are tight enough so there's not a leak from them. if i leave it to idle the engine gradually dies.
i did the tps setting adjustment a couple of weeks ago but it was running fine after that, it has only got these problems a week ago.

if anyone has any ideas what it is or what to check it would be much appreciated.

cheers
matt

Checked all the air box hoses are connected?

[Bibio]

how tight is tight on the spark plugs?

the plugs on the sv are quite delicate and only require a 1/4 turn to seat them. i know this as i have ripped a thread of the bottom before and i'm not one for 'beefing' things up.

[muzikill]

The sv hose clips to a from the airbox on my k3 are horribly inadequate & are likely to lose tension over a number of years especially if they are disturbed in any way after a long period of time of never been touched. Theres no harm in lifting the tank to check. If youve replaced the spark plugs then you must have done this before.

Can the bike be run with a lifted tank? - if so its going to make it easier to spot.

[tj2]

Sounds to me like the fuel pump (hissing noise and intermittant) have you traped a fuel line when the tank went back down last time?

Terry

turns out it was the jubilee clip on the rear rubber inlet to the air box, it was loose and the thread had been striped somehow, so i replaced it with a new clip and it is now running perfectly.
thanks for all the replies.

matt