Went to do an oil and filter change on my Z900 and the bloody 17mm sump drain plug is seized solid and won't budge!
The oil and filter were last changed in June 2017 (2,500 miles ago), but I haven't used the bike for the last year, other than to start it up every now and again.
I've tried a 12" extension bar, but it won't budge other than bike wobbles on the centre stand!

Don't want to strip the bolt head so haven't gone near it my impact wrench, but if this was one of my old Triumph cars I'd use my blow lamp but with the Z900 engine being alloy I'm hovering on that idea.
Any suggestions gratefully received.