Sam,
Breaking in process is crucial,mine started p,ing petrol from one of the float inlets so had to turn it off straight away,then an oil leak.
This was my 1500 that i spent a fortune on,ended up grenading after 500 miles.Cracked head let water in the bore.
On another note, I was on the Raiders run (Blue Vitesse) when your old one dropped a valve,hope it all goes well for you.
Steve