Mine was on really tight on my Eclipse impy. Tried heating it with a drier, steeping it in boiling water, the works... In the end I had to drill a hole through it and wedge a screw driver through it and twist it off. I say I did, well one of the lads did
Had tried the strap wrench thing as well with no joy...
Make sure it is an Impy with a threaed feed neck as well, some of the early ones were actually bonded in there