I've just joined the forum and I'm hoping that someone can advise me on how to remove the retaining nut on the front sprocket. 

Is it normal right hand thread or is it left handed and I'd there a way of locking the output shaft without damaging it when trying to undo the nut. 

All advise greatly welcome, cheers. 

Turn the counter shaft sprocket nut clockwise to loosen it. This also applies to the magneto / flywheel nut. They are most easily removed with an impact hammer.

Leave the chain on and you can jam the wheel to hold the sprocket still to undo the nut

Thanks guys. I'll give this a go and see how I get on, cheers.