need a spec diagram for a McCullough Titan 50/57 chainsaw?

I have a McCullough Titan 50/57 chainsaw approximately 15-16 yrs old I bought new. There is a fuel leak as you add gas. The local chainsaw repairman says there are 3 lines in there assuming one is a vacuum/air filter(?) of some sort. He is stumped and needs to see a diagram in order to determine what and where these lines go and are.