need help my s2 wont start.i turn the keyit starts up then it stalls,it starts up again then stalls straight away,then it wont start,i leave it for 20 seconds then it starts again,and does the same thing.before this happened it was struggling to start up it took a good while ,i took a look at it and found the bottom boost hose loose.tightend it up and it started ok,next day tried it took a few turns then it started,once its running its ok,can anyone help.

 

Possible air leak somewhere? breather/boost hose maybe..