MZ/MuZ Riders

hi folks,
collective wisdom required, I need to change the front sprocket, (new chain & sprockets) and I cannot undo the nut holding the sprocket, I`ve tried long extension leaver + my 16 stone, some gentle heat and hammering a punch onto the nut, but, it just wont budge!! any suggestions ?
cheers Eric.
p/s sudden thought is it a left handed thread by any chance???

Right handed nut!

More heat and a longer "cheater bar" on the wrench?

Silly question, but did you remove or bend the locking tab out of the way?

If it doesn't have a locking device, I would find an impact wrench. It seems to me like they would do less damage to the transmission than using a large pry bar. I bought a cheapo electric impact from Harbor Freight and some oversized sockets that will get the job done.

thanks, guys,
I was obviously being too gentle with it !!
I've now got myself the use of an impact driver / wrench and a 12 point socket the nut WILL come off, this time
cheers Eric.

if it does not
that impact will put a twist in your knickers