Thanks wce and NormK for your reply.

It looks like i have a few things to do here but just need to clarify the parts you're referring to : :

1. Remove coil - which is the coil ? is this where the spark plug wire is connected to ?
2. Clean the flywheel magnets - I assumed the flywheel magnets is the rusted part. It must have rusted when i stored the mower just under the roof.
3. Clean Coil pick up - not sure where is this.
4. Set air gap - where is this gap.
5. Sand up the face of the coil legs - where are coil legs
6. is the coil gaps the same as the air gap mentioned by wce.

Sorry about all the questions as i don't have a parts diagram of where are all this and i'm not totally familiar with the terminology.