Finally got it all sorted, BHDave was right, it was 5/16" i needed. Looks like when i got my 100K service done and they replaced my fuel line from the top of the filter to the manifold, they put the wrong size hose on, a 3/16" one.
This time i checked the one that the NRMA guy put on (the one below the filter, which is the one that burst) and realised it was 5/16".
Wish i had've read BHDaves reply earlier, bloody mech that replaced the fuel line must've been a dud.
Quick question, will the fact that the fuel hose was too small have starved the engine of petrol at higher revs?? I'd noticed it wasn't running as well as usual but don't know if that was the cause.