Fix problem Gardenmaster 80 cultivator

Please help me fix a problem I have with my Landmaster Gardenmaster 80.

After a few attempts to start it, it will make some very satisfying engine noises for about one second. I even get a puff of smoke. But, I can't get the engine to run further.

The previous owner told me he had it running on a 40:1 mix. But, I bought it blind and didn't see it running.
The data printed on the frame clearly states "One part Castrol XL (SAE 30) oil mixed with 24 parts petrol.". So, I am considering draining the fuel and replacing it with this richer mix.

The other matter is the spark plug.
When I was given this cultivator it came fitted with a NGK spark plug BPMR6A/130-815.
Now, based on the fact that the fuel mix was not correct, I did a quick Internet search and discovered some information on another forum. And apparently the correct spark plug should be equivalant to a Champion L86C/130. The NGK equivalent is B6HS/130-712. I don't know much about spark plugs. But I do know that it is important you have the correct one fitted and set the gap correctly.
I am hoping someone can point me in the right direction.
A photocopy of the manual would be great.

Thanks Grendel.

I've printed off the manual for the Landmaster 85 rotovator from the manuals folder.

It looks the closest to my Gardenmaster 80, although obviously it is not the same machine. How much of this is cosmetic and how it differs mechanically I would not really like to guess. It may be risky to assume too much, like spark plug type/setting etc. But, I guess it is better than nothing.

I am hoping someone on the site has the same machine in good running order, or a manual for the #80.

I appreciate your help.