Hi;Still fighting with this engine.TRhink I said earlier it was a 120,my mistake is didn't look at side of engine when ai put it in is a 91AC.Tried it again today still no luck!.Fuel leaking out around the regulator,had a new diaphram int it afraid to tighten to it and strip threads .Also has fuel gushing off the airbox on back of engine.This is first attempt to run engine since returned from the YS shop where they replaced all gaskets etc for this problem.Ican't see any damamge to the regulator housing that should cause a leak?Checked all bolts on the airbox in back etc seemed tight.Engine is inverted which I hate but how the Harrier is set up.Fuel seems to be coming off the top?of the airbox and running down can't seem to see where it is coming from as is all covered with fuel running off it.Will carefully look for cracks was tired of looking at it yesterday.Maybe have to send it back again but this is the reason was sent in!Also had sent my 120 at same time same problem but haven't had anything to mount it in to try it!Thanks for your hints!!!